Orthopaedic surgical procedure for implanting a revision hip prosthesis

ABSTRACT

A modular femoral prosthesis for use during performance of a hip revision procedure includes a proximal body component, a distal stem component, and a locking bolt. Surgical instruments and methods for use in implanting such a modular femoral prosthesis are disclosed.

This application is a divisional application of, and claims priority toU.S. patent application Ser. No. 13/440,448, now U.S. Pat. No. ______,which was filed on Apr. 5, 2012, which claims priority under 35 U.S.C.§119(e) to U.S. Provisional Patent Application Ser. No. 61/472,500 whichwas filed on Apr. 6, 2011, the entirety of each of which is herebyincorporated by reference.

CROSS REFERENCE

Cross reference is made to copending U.S. patent application Ser. No.13/440,397, now U.S. Pat. No. 8,702,807, entitled “REVISION HIPPROSTHESIS HAVING AN IMPLANTABLE DISTAL STEM COMPONENT”; copending U.S.patent application Ser. No. 13/440,406 entitled “DISTAL REAMER FOR USEDURING AN ORTHOPAEDIC SURGICAL PROCEDURE TO IMPLANT A REVISION HIPPROSTHESIS”; copending U.S. patent application Ser. No. 13/440,425entitled “PROXIMAL TRIAL INSTRUMENT FOR USE DURING AN ORTHOPAEDICSURGICAL PROCEDURE TO IMPLANT A REVISION HIP PROSTHESIS”; copending U.S.patent application Ser. No. 13/440,430 entitled “FINISHING RASP ANDORTHOPAEDIC SURGICAL PROCEDURE FOR USING THE SAME TO IMPLANT A REVISIONHIP PROSTHESIS”; copending U.S. patent application Ser. No. 13/440,433entitled “VERSION-REPLICATING INSTRUMENT AND ORTHOPAEDIC SURGICALPROCEDURE FOR USING THE SAME TO IMPLANT A REVISION HIP PROSTHESIS”; andcopending U.S. patent application Ser. No. 13/440,443 entitled“INSTRUMENT ASSEMBLY FOR IMPLANTING A REVISION HIP PROSTHESIS ANDORTHOPAEDIC SURGICAL PROCEDURE FOR USING THE SAME”, each of which isassigned to the same assignee as the present application, each of whichis filed concurrently herewith, and each of which is hereby incorporatedby reference.

TECHNICAL FIELD

The present disclosure relates generally to orthopaedic instruments foruse in the performance of an orthopaedic joint replacement procedure,and more particularly to orthopaedic instruments for use in theperformance of a revision hip replacement procedure.

BACKGROUND

During the lifetime of a patient, it may be necessary to perform a jointreplacement procedure on the patient as a result of, for example,disease or trauma. The joint replacement procedure may involve the useof a prosthesis which is implanted into one of the patient's bones. Inthe case of a hip replacement procedure, a femoral prosthesis isimplanted into the patient's femur. Such a femoral prosthesis typicallyincludes a spherically-shaped head which bears against the patient'sacetabulum, along with an elongated intramedullary stem which isutilized to secure the femoral component to the patient's femur. Tosecure the prosthesis to the patient's femur, the intramedullary canalof the patient's femur is first surgically prepared (e.g. reamed and/orbroached) such that the intramedullary stem of the femoral prosthesismay be subsequently implanted therein.

During performance of such a hip replacement procedure, it is generallynecessary to provide the surgeon with a certain degree of flexibility inthe selection of a prosthesis. In particular, the anatomy of the boneinto which the prosthesis is to be implanted may vary somewhat frompatient to patient. For example, a given patient's femur may berelatively long or relatively short thereby requiring use of a femoralprosthesis which includes a stem that is relatively long or short,respectively. Moreover, in certain cases, such as when use of arelatively long stem length is required, the stem must also be bowed inorder to conform to the anatomy of the patient's femur.

As a result, modular prostheses have been designed. As its name implies,a modular prosthesis is constructed in modular form so the individualcomponents of the prosthesis can be selected to fit the needs of a givenpatient's anatomy. For example, a typical modular prosthesis includes aproximal body component that can be assembled to any one of numerousdistal stem components. Such a design allows the distal stem componentto be selected and thereafter implanted in the patient's bone in aposition which conforms to the patient's anatomy while also allowing fora degree of independent positioning of the proximal body componentrelative to the patient's acetabulum.

From time-to-time, a revision hip surgery may need to be performed on apatient. In such a revision hip surgery, the previously implanted hipprosthesis is surgically removed and a replacement hip prosthesis isimplanted in the patient's femur.

SUMMARY

According to one aspect, a modular femoral prosthesis for use duringperformance of a hip revision procedure includes a proximal bodycomponent, a distal stem component, and a locking bolt.

According to another aspect, a starter reamer may be used to ream theintramedullary canal of a patient's femur during an orthopaedic surgicalprocedure to implant the modular femoral prosthesis.

According to another aspect, a distal reamer may be used to ream theintramedullary canal of a patient's femur subsequent to use of thestarter reamer.

The distal reamer may be left in the intramedullary canal of a patient'sfemur subsequent to its use. A proximal trial instrument may then becoupled to the distal reamer and a trial reduction performed to confirmthe appropriate leg length, component orientation, and offset.

According to another aspect, a reamer guide shaft may be coupled to thedistal reamer while the reamer is positioned in the intramedullary canalof a patient's femur.

According to another aspect, a finishing rasp may be used to rasp thepatient's femur.

According to yet another aspect, the distal stem component may becoupled to a stem insertion tool to facilitate implantation of the stemcomponent into the intramedullary canal of a patient's femur.

According to another aspect, a proximal reamer may be used to ream thepatient's femur to facilitate implantation of the proximal bodycomponent.

According to a further aspect, the proximal trial instrument may becoupled to a trial insertion tool and then secured to the implanteddistal stem component.

According to another aspect, a version-replicating instrument may becoupled to the implanted distal stem component. The version of theproximal body component may be adjusted to match the version of theproximal trial instrument by use of the version-replicating instrument.

According to yet another aspect, a surgical tamp may be used toinitially engage the taper lock connection between the distal stemcomponent and the proximal body component.

According to another aspect, a stem stabilizer and a torque wrench maybe used to install a locking bolt to lock the proximal body component tothe distal stem component.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description particularly refers to the following figures,in which:

FIG. 1 is a perspective view of a proximal body component of a modularfemoral prosthesis for use during performance of a hip revisionprocedure;

FIG. 2 is cross sectional view of the proximal body component of FIG. 1;

FIG. 3 is an elevation view of a distal stem component of a modularfemoral prosthesis for use along with the proximal body component duringperformance of a hip revision procedure;

FIG. 4 is a top elevation view of the distal stem component of FIG. 3;

FIG. 5 is a cross sectional view of the distal stem component takenalong the line 5-5 of FIG. 3, as viewed in the direction of the arrows;

FIG. 6 is an enlarged fragmentary cross sectional view showing thedistal stem component in greater detail, with FIG. 6 being taken fromFIG. 5 as indicated by the encircled area;

FIG. 7 is an elevation view of the starter reamer used to surgicallyprepare the femur of the patient during performance of a hip revisionprocedure;

FIG. 8 is a manual handle that may be used to drive the variousinstruments described herein;

FIG. 9 is an elevation view of the distal reamer used to surgicallyprepare the femur of the patient during performance of a hip revisionprocedure;

FIG. 10 is an enlarged cross sectional view of the distal reamer takenalong the line 10-10 of FIG. 9, as viewed in the direction of thearrows;

FIG. 11 is a perspective view of the extension tool used to drive thedistal reamer of FIGS. 9 and 10 during performance of a hip revisionprocedure;

FIG. 12 is an elevation view of the extension tool of FIG. 11;

FIG. 13 is a cross sectional view of the extension tool taken along theline 13-13 of FIG. 12, as viewed in the direction of the arrows;

FIG. 14 is a perspective view of the trial shaft of the proximal trialinstrument used to perform a trial reduction during performance of a hiprevision procedure;

FIGS. 15 and 16 are elevation views of the trial shaft of FIG. 14;

FIG. 17 is a cross sectional view of the trial shaft taken along theline 17-17 of FIG. 15, as viewed in the direction of the arrows;

FIG. 18 is a top elevation view of the trial neck of the proximal trialinstrument used to perform a trial reduction during performance of a hiprevision procedure, note a portion of the trial neck has been cutaway toshow the trial neck's friction clamp in greater detail;

FIG. 19 is an elevation view of the trial neck of FIG. 18;

FIG. 20 is a cross sectional view of the trial neck taken along the line20-20 of FIG. 18, as viewed in the direction of the arrows;

FIG. 21 is a perspective view of the reamer guide shaft used to guide anumber of instruments during performance of a hip revision procedure;

FIG. 22 is an elevation view of the reamer guide shaft of FIG. 21;

FIG. 23 is a cross sectional view of the reamer guide shaft taken alongthe line 23-23 of FIG. 22, as viewed in the direction of the arrows;

FIG. 24 is an elevation view of the finishing rasp used to surgicallyprepare the femur of the patient during performance of a hip revisionprocedure;

FIG. 25 is a cross sectional view of the finishing rasp taken along theline 25-25 of FIG. 24, as viewed in the direction of the arrows;

FIG. 26 is an elevation view of the stem insertion tool used tosurgically implant the distal stem component into the femur of thepatient during performance of a hip revision procedure;

FIG. 27 is a cross sectional view of the stem insertion tool taken alongthe line 27-27 of FIG. 26, as viewed in the direction of the arrows;

FIG. 28 is a perspective view of the taper-protecting sleeve used toprotect the taper of the distal stem component during performance of ahip revision procedure;

FIG. 29 is an enlarged cross sectional view of the taper-protectingsleeve of FIG. 28;

FIG. 30 is a perspective view of the proximal reamer used to surgicallyprepare the femur of the patient during performance of a hip revisionprocedure;

FIG. 31 is an elevation view of the proximal reamer of FIG. 30;

FIG. 32 is a cross sectional view of the proximal reamer taken along theline 32-32 of FIG. 31, as viewed in the direction of the arrows;

FIG. 33 is a perspective view of the trial insertion tool used toinstall the proximal trial instrument of FIGS. 14-20 during performanceof a hip revision procedure;

FIG. 34 is a side elevation view of the trial insertion tool with itsretention socket being shown in cross section for clarity ofdescription;

FIG. 35 is an enlarged elevation view of the retention socket of thetrial insertion tool;

FIG. 36 is a perspective view of the version-replicating instrument usedduring performance of a hip revision procedure;

FIG. 37 is a side elevation view of the version-replicating instrumentof FIG. 36;

FIG. 38 is an enlarged cross sectional view of the distal end of theversion-replicating instrument taken along the line 38-38 of FIG. 37, asviewed in the direction of the arrows;

FIG. 39 is an enlarged cross sectional view of the proximal end of theversion-replicating instrument taken along the line 39-39 of FIG. 36, asviewed in the direction of the arrows;

FIG. 40 is a perspective view of the stem stabilizer used duringperformance of a hip revision procedure;

FIG. 41 is an enlarged perspective view of the drive rod of the stemstabilizer of FIG. 40;

FIG. 42 is a side elevation view of the stem stabilizer of FIG. 40;

FIG. 43 is a view similar to FIG. 42, but showing a portion of the stemstabilizer in cross section for clarity of description;

FIG. 44 is a fragmentary elevation view showing the starter reamer beingused to ream the intramedullary canal of a patient's femur duringperformance of a hip revision procedure;

FIG. 45 is a fragmentary elevation view showing the extension tool andthe distal reamer being used to ream the intramedullary canal of apatient's femur during performance of a hip revision procedure;

FIG. 46 is a fragmentary elevation view showing the proximal trialinstrument coupled to the distal reamer during performance of a hiprevision procedure;

FIG. 47 is a fragmentary elevation view showing the reamer guide shaftcoupled to the distal reamer during performance of a hip revisionprocedure;

FIGS. 48 and 49 are fragmentary elevation views showing the finishingrasp being used to rasp the patient's femur during performance of a hiprevision procedure;

FIG. 50 is a fragmentary elevation view showing the distal stemcomponent being coupled to the stem insertion tool during performance ofa hip revision procedure;

FIG. 51 is a fragmentary elevation view showing the stem insertion toolbeing used to implant the distal stem component into the intramedullarycanal of a patient's femur during performance of a hip revisionprocedure;

FIG. 52 is a fragmentary elevation view showing the reamer guide shaftsecured to the distal stem component during performance of a hiprevision procedure;

FIG. 53 is a fragmentary elevation view showing the proximal reamerbeing used to ream the patient's femur during performance of a hiprevision procedure;

FIGS. 54-56 are elevation views showing the trial insertion tool beingused to couple the proximal trial instrument to the distal stemcomponent during performance of a hip revision procedure;

FIG. 57 is an enlarged fragmentary perspective view showing the versionof the trial neck being adjusted during performance of a hip revisionprocedure;

FIG. 58 is a fragmentary elevation view showing the version-replicatinginstrument and the proximal body component being coupled to theimplanted distal stem component during performance of a hip revisionprocedure;

FIG. 59 is an enlarged elevation view showing the version-replicatinginstrument and the distal stem component in greater detail, with FIG. 59being taken from FIG. 58 as indicated by the encircled area, note FIG.59 has been rotated 90° relative to FIG. 58 for clarity of description;

FIG. 60 is a fragmentary elevation view showing the proximal trialinstrument being coupled to the version-replicating instrument duringperformance of a hip revision procedure;

FIG. 61 is a fragmentary elevation view showing the version of theproximal body component being adjusted to match the version of theproximal trial instrument by use of the version-replicating instrumentduring performance of a hip revision procedure;

FIGS. 62 and 63 are fragmentary elevation views showing a surgical tampbeing used to initially engage the taper lock connection between thedistal stem component and the proximal body component during performanceof a hip revision procedure;

FIG. 64 is a fragmentary elevation view showing the locking bolt beinginserted into the proximal body component during performance of a hiprevision procedure;

FIGS. 65 and 66 are fragmentary elevation views showing the locking boltbeing tightened by use of the stem stabilizer and the T-shaped torquewrench during performance of a hip revision procedure;

FIG. 67 is a perspective view of the locking bolt of the modular femoralprosthesis for use along with the proximal body component and the distalstem component during performance of a hip revision procedure;

FIG. 68 is an elevation view of the locking bolt of FIG. 67;

FIG. 69 is a cross sectional view of the locking bolt taken along theline 69-69 of FIG. 68, as viewed in the direction of the arrows;

FIG. 70 is an enlarged cross sectional view showing the locking bolt ingreater detail, with FIG. 70 being taken from FIG. 69 as indicated bythe encircled area;

FIG. 71 is an elevation view of another embodiment of a trial insertiontool used during performance of a hip revision procedure;

FIG. 72 is a cross sectional view of the trial insertion tool takenalong the line 72-72 of FIG. 71, as viewed in the direction of thearrows; and

FIG. 73 is an enlarged cross sectional view of the retention socket ofthe trial insertion tool taken along the line 73-73 of FIG. 72, asviewed in the direction of the arrows.

DETAILED DESCRIPTION OF THE DRAWINGS

While the concepts of the present disclosure are susceptible to variousmodifications and alternative forms, specific exemplary embodimentsthereof have been shown by way of example in the drawings and willherein be described in detail. It should be understood, however, thatthere is no intent to limit the concepts of the present disclosure tothe particular forms disclosed, but on the contrary, the intention is tocover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the invention.

Terms representing anatomical references, such as anterior, posterior,medial, lateral, superior, inferior, et cetera, may be used throughoutthis disclosure in reference to both the orthopaedic implants describedherein and a patient's natural anatomy. Such terms have well-understoodmeanings in both the study of anatomy and the field of orthopaedics. Useof such anatomical reference terms in the specification and claims isintended to be consistent with their well-understood meanings unlessnoted otherwise.

Referring now to FIGS. 1-5, there is shown a modular femoral prosthesis10 for use during performance of a hip replacement procedure. Themodular femoral prosthesis 10 includes a proximal body component 12 anda distal stem component 14. As will be discussed below in regard toFIGS. 64-66, the modular femoral prosthesis also includes a locking bolt504 that provides a secondary lock between the proximal body component12 and the distal stem component 14 (the primary lock being the taperlock described below). The prosthesis 10 is configured to be implantedinto a femur 20 (see FIGS. 40-57) of a patient during a hip revisionprocedure. In particular, the modular prosthesis 10 is implanted into asurgically prepared (e.g. reamed and/or broached) intramedullary canal22 of the patient's femur 20.

A head component (not shown) is secured to the end of the elongated neck16 of the proximal body component 12 to bear on either the patient'snatural acetabulum or a prosthetic socket which has been implanted intothe patient's pelvis to replace his or her acetabulum. In such a manner,the modular femoral prosthesis 10 and the natural or artificialacetabulum collectively function as a system which replaces the naturaljoint of the patient's hip.

The distal stem component 14 may be provided in a number of differentconfigurations in order to fit the needs of a given patient's anatomy.In particular, the stem component 14 may be configured in variousdifferent lengths to conform to the patient's anatomy (e.g. a relativelylong stem component 14 for use with a long femur 20, a relatively shortstem for use with a short femur 20, et cetera). Moreover, the distalstem component 14 may also be provided in a bow-shaped configuration ifrequired by a given patient's anatomy. Yet further, the distal stemcomponent 14 may also be provided in various diameters if required by agiven patient's anatomy. In one illustrative embodiment, the stemcomponent 14 may be provided in four different lengths—140 mm, 190 mm,240 mm, and 290 mm Such stem components are provided in 1 mm diameterincrements ranging from 14 to 31 mm, although in some embodimentscertain of the sizes in such a range (e.g., 28 mm and 30 mm) may beomitted. In such an illustrative embodiment, straight stem componentsare available in the two shorter lengths (i.e., 140 mm and 190 mmlengths), with the three longer stem lengths (i.e., 190 mm, 240 mm, and290 mm) being available with a 3° angle to accommodate the curvature ofthe femoral anterior bow.

Likewise, the proximal body component 12 (and the head component securedthereto) may also be provided in various different configurations toprovide the flexibility necessary to conform to varying anatomies frompatient to patient. For example, the proximal body component 12 may beprovided in four different lengths—75 mm, 85 mm, 95 mm, and 105 mm Likethe distal stem component 14, the proximal body component 12 may also beprovided in various diameters. For example, in one illustrativeembodiment, the proximal body component 12 may be provided in threedifferent diameters—20 mm, 24 mm, and 28 mm The offset of the proximalbody component 12 may be varied to increase the offset of the prosthesis10. The head component may be provided in varying diameters to fit theneeds of a given patient's anatomy.

As shown in FIGS. 1 and 2, the proximal body component 12 includes abody 24, with the neck 16 extending medially therefrom. The headcomponent (not shown) is taper fit or otherwise secured to the end ofthe elongated neck 16. The body 24 also has an tapered bore 28 formedtherein. A tapered post 30 of the distal stem component 14 (see FIGS.3-6) is received into the tapered bore 28 of the proximal body component12. As will be discussed below in greater detail below, urging thetapered post 30 of the distal stem component 14 and the sidewalldefining the tapered bore 28 of the proximal body component 12 towardone another taper locks the proximal body component 12 to the distalstem component 14.

The superior surface of the body 24 of the proximal body component 12has a countersunk cavity 32 formed therein. The inferior side of thecountersunk cavity 32 opens into a locking recess 34. The inferior sideof the locking recess 34 opens into a connecting bore 36, which in turnopens into the tapered bore 28. As will be discussed below in greaterdetail, a locking bolt 504 (see FIG. 64) is inserted through thecountersunk cavity 32 and thereafter extends through the connecting bore36 to engage the distal stem component 14.

As shown in FIGS. 3-6, the tapered post 30 is formed in the superior endof the body 38 of the distal stem component 14. The superior surface ofthe body 38 of the distal stem component 14 has a set of upper threads40 formed therein. As will be discussed below in more detail, the upperthreads 40 are used to couple the distal stem component 14 to surgicalinstruments that are impacted during use thereof. A set of lower threads42 are positioned inferiorly of the upper threads 40. The lower threads42 are used to couple the distal stem component 14 to the locking bolt504 (see FIG. 64) of the hip prosthesis 10, along with those surgicalinstruments that are not impacted during their use. By not subjectingthe lower threads to impacted surgical instruments during implantationof the femoral prosthesis 10, the threads ultimately used to secure theprosthesis's bolt (i.e., the lower threads 42) are protected from damageduring the surgical procedure. In the exemplary embodiment describedherein, the upper threads 40 are M8 size threads, whereas the lowerthreads 42 are M6 size threads.

In the illustrative embodiment described herein, the lower threads 42are embodied as modified threads designed to relieve stress risers. Inparticular, as can be seen best in FIG. 6, the outer edges 54 of thelower threads 42 are rounded. Unexpectedly, testing and modeling haveshown that such rounded edges 54 provide relief from stress risers inthe distal stem component 14. Additional relief from stress risers isalso provided by the design of the distal end of the blind hole in whichthe lower threads 42 are formed. In particular, in lieu of a point orother geometry, the distal end 56 of the blind hole extendingposteriorly from the lower threads 42 is rounded. That is, the blindhole formed in the body 38 of the distal stem component 14 that extendsposteriorly from the threads 42 has a rounded distal end 56. Like therounded outer edges 54 of the lower threads 42, testing and modelinghave unexpectedly shown that such a rounded distal end 56 providesrelief from stress risers in the distal stem component 14.

An alignment key 44 in the form of, for example, a tab extendssuperiorly from the superior surface of the body 38 of the distal stemcomponent 14. The alignment key 44 is in line with the apex of thedistal stem component 14. That is, bowed stem components 14 have an apex(i.e., a spine) that runs along the convex side of its curvature. Duringimplantation of the distal stem component 14, the apex must be properlyaligned with the corresponding side of the patient's femur 20 possessinga similar curvature. As will be described below, the alignment key 44facilitates proper orientation of the apex of the distal stem component14 by allowing the surgeon to visualize the location of the apex evenwhen the stem component 14 is positioned in the intramedullary canal.

As can be seen in FIG. 4, a keyway 46 is formed in the superior surfaceof the body 38 of the distal stem component 14. The keyway 46 is formedin the sidewall 48 that defines the outer opening 50 of the upperthreads 40. In the exemplary embodiment described herein, the keyway 46is embodied as a lobe-shaped slot configured to receive a lobe-shapedkey of a surgical trial instrument, although other shaped slots and tabsmay be used. As will be discussed below, such a feature allows a trialedorientation of a proximal trial body component to be replicated for usein implanting the proximal body component 12.

Referring now to FIGS. 7-43, there are shown the various instrumentsused to implant the femoral prosthesis 10 into the intramedullary canal22 of the patient's femur 20. In FIG. 7, there is shown a starter reamer60 that may be used during the initial steps of the surgical preparationof the patient's femur 20. The starter reamer 60 is used to ream theportion of the patient's intramedullary canal 22 into which the distalstem component 14 is implanted. The starter reamer 60 includes anelongated shank 62 having a proximal end 64 that fits into the chuck ofa rotary power tool 86 (see FIG. 45) or a manual handle 80 (see FIGS. 8and 44). The starter reamer 60 also includes a cutting head 66 locatedat the opposite, distal end of the shank 62. The cutting head 66 of thestarter reamer 60 includes a sharp cutting tip 68 with a plurality ofhelical cutting flutes 70 extending therefrom. The cutting tip 68 cutsthrough any debris or cement remnants from the previously-removedfemoral prosthesis. When the starter reamer 60 is positioned in theintramedullary canal 22 of the patient's femur 20 and rotated, thecutting head 66 reams or otherwise cuts the bone tissue of the femurthereby obtaining clear access to the femoral canal. Such access to thefemoral canal ensures proper alignment of the components of the femoralprosthesis 10.

The starter reamer 60 includes a number of colored depth marks 72, 74,76, 78 formed on its shank 62 at a location above the proximal end ofthe cutting head 66. Each of the colored depth marks 72, 74, 76, 78corresponds to the standard head center of a number of differentproximal body components 12. For example, the proximal body component 12may be provided in four different lengths—75 mm, 85 mm, 95 mm, and 105mm In the exemplary embodiment described herein, the depth mark 72 isblue and corresponds to the location of the center of the head of a 75mm proximal body component 12, the depth mark 74 is green andcorresponds to the location of the center of the head of a 85 mmproximal body component 12, the depth mark 76 is yellow and correspondsto the location of the center of the head of a 95 mm proximal bodycomponent 12, and the depth mark 78 is red and corresponds to thelocation of the center of the head of a 105 mm proximal body component12. The depth marks 72, 74, 76, 78 may be embodied as grooves engravedin the shank 62, each of which is filled with an epoxy ink of thecorresponding color. During a surgical procedure, the starter reamer 60is advanced deeper into the intramedullary canal 22 of the patient'sfemur 20 until the desired depth mark aligns with the tip 82 of thegreater trochanter 84 (see FIG. 44) and clear access to the canal 22 isachieved. In such a way, over reaming of the distal end of the canal 22is avoided if the starter reamer 60 is not driven beyond the appropriatecolored depth mark 72, 74, 76, 78.

A male connector 88 is formed in the proximal end 64 of the shank 62 ofthe starter reamer 60. The connector 88 fits into the chuck of a rotarypower tool 86 (see FIG. 45) or a manual handle 80 (see FIG. 8) to couplethe starter reamer 60 to a rotary drive source.

The starter reamer 60 may be constructed from a medical-grade metal suchas stainless steel, cobalt chrome, or titanium, although other metals oralloys may be used. Moreover, in some embodiments, rigid polymers suchas polyetheretherketone (PEEK) may also be used.

Referring now to FIGS. 9 and 10, there is shown a distal reamer 90 thatmay be used after the starter reamer 60 during the surgical preparationof the patient's femur 20. Like the starter reamer 60, the distal reamer90 is used to ream the portion of the patient's intramedullary canal 22into which the distal stem component 14 is implanted. The use ofprogressively larger distal reamers 90 produces a bore possessing thefinal geometry (i.e., the shape) required to accept the distal stemcomponent 14 of the femoral prosthesis 10. The distal reamer 90 includesan elongated shank 92 having a proximal end 94 that mates with anextension tool 120 (see FIGS. 11-13). As will be described below ingreater detail, the extension tool 120 may in turn be secured to thechuck of the rotary power tool 86 (see FIG. 45) or the manual handle 80(see FIG. 8).

The distal reamer 90 also includes a cutting head 96 located at theopposite, distal end 98 of the shank 92. The cutting head 96 of thedistal reamer 90 includes a plurality of helical cutting flutes 100. Theouter cutting surfaces of the cutting flutes 100 are tapered to mimicthe geometry of the distal stem component 14. When the distal reamer 90is positioned in the intramedullary canal 22 of the patient's femur 20and rotated, the cutting flutes 100 ream or otherwise cut the bonetissue of the femur 20.

To accommodate the various different configurations of the distal stemcomponents 14, the distal reamer 90 may likewise be provided in a numberof different configurations. In particular, the distal reamer 90 may beconfigured in various different lengths to produce a reamed bore of asize sufficient to receive distal stem components 14 of variousdifferent lengths (e.g. a relatively long distal reamer 90 to preparethe femur 20 for implantation of a relatively long stem component 14, arelatively short distal reamer 90 to prepare the femur 20 forimplantation of a relatively short stem component 14, et cetera). Yetfurther, the distal reamer 90 may be provided in a number of variousdiameters to produce a reamed bore of the diameter sufficient to receivedistal stem components 14 of various diameters. In one illustrativeembodiment, the distal reamer 90 may be provided in four differentlengths—140 mm, 190 mm, 240 mm, and 290 mm Such reamers 90 are providedin 1 mm diameter increments ranging from 14 to 31 mm

The proximal end 94 of the distal reamer 90 has a countersunk driveconnector 102 formed therein. The drive connector 102 is shaped toreceive the locking jaws 148 and the drive spline 126 of the extensiontool 120 (see FIGS. 11-13). The sidewall 104 that defines the driveconnector 102 has a number of L-shaped locking slots 106 definedtherein. Positioned posteriorly of the locking slots 106, the sidewall104 that defines the drive connector 102 has a female drive socket 108defined therein. In the illustrative embodiment described herein thefemale drive socket 108 is embodied as a female hex drive socket thecompliments the size and shape of the drive spline 126 of the extensiontool 120. As will described below in regard to FIGS. 11-13, the lockingjaws 148 of the extension tool 120 may be positioned in the lockingslots 106 and thereafter engaged with the sidewall 104 to selectivelylock the extension tool 120 to the proximal end 94 of the distal reamer90. In doing so, the extension tool's drive spline 126 is received intothe female drive socket 108 of the distal reamer 90. When the extensiontool 120 is locked to the distal reamer 90 in such a way, rotation ofthe extension tool's drive spline 126 causes rotation of the distalreamer 90.

As can be seen in the cross section of FIG. 10, the proximal end of ablind bore 110 opens into the connector 102. The blind bore 110 extendsdistally away from the female drive socket 108. The upper end of theblind bore 110 is threaded. Namely, a number of threads 112 are formedin the sidewall that defines the proximal end of the blind bore 110. Inthe illustrative embodiment described herein, the threads 112 do notextend throughout the length of the blind bore 110. As a result, thebore's distal end is smooth (i.e., not threaded). The threads 112 aresized to match the lower threads 42 of the distal stem component 14. Assuch, in the illustrative embodiment described herein, the threads 112are M6 size threads.

Like the starter reamer 60, the distal reamer 90 may be constructed froma medical-grade metal such as stainless steel, cobalt chrome, ortitanium, although other metals or alloys may be used. Moreover, in someembodiments, rigid polymers such as polyetheretherketone (PEEK) may alsobe used.

Referring now to FIGS. 11-13, there is shown an extension tool 120 thatmay be used in conjunction with the distal reamer 90 during the surgicalpreparation of the patient's femur 20. The extension tool 120 may beused to drive the distal reamer 90 to ream the portion of the patient'sintramedullary canal 22 into which the distal stem component 14 isimplanted. The extension tool 120 includes an elongated drive shaft 122having a proximal end 124 that fits into the chuck of a rotary powertool 86 (see FIG. 45) or a manual handle 80 (see FIG. 8). The extensiontool 120 also includes a drive spline 126 located at the opposite,distal end 128 of the drive shaft 122. The drive spline 126 of theextension tool 120 includes a plurality of drive teeth 130. When thedrive teeth 130 of the drive spline 126 are positioned in the femaledrive socket 108 of the distal reamer 90, the drive shaft 122 is coupledto the distal reamer 90. As such, rotation of the drive shaft 122 causesrotation of the distal reamer 90.

The drive shaft 122 of the extension tool 120 includes an elongatedshaft body 132. A male connector 134 is formed in the proximal end 136of the shaft body 132. The connector 134 fits into the chuck of a rotarypower tool 86 (see FIG. 45) or a manual handle 80 (see FIG. 8) to couplethe drive shaft 122 to a rotary drive source. A sleeve 138 is positionedaround the shaft body 132. The sleeve 138 is coupled to the outersurface of the shaft body 132 through a bearing 140. As such, the shaftbody 132 (and hence the drive shaft 122) rotates freely of the sleeve138. The sleeve 138 functions as a grip for allowing the surgeon to holdthe extension tool 120 during rotation of the drive shaft 122.

An elongated tip 142 extends distally away from the distal end of theshaft body 132. In particular, a proximal end 144 of the elongated tip142 is secured to the distal end 146 of the shaft body 132. Theelongated tip 142 has a pair of locking flanges 148 formed in its distalend. The locking jaws 148 face oppositely one another. The tip 142 hasan elongated bore 150 extending therethrough. The distal end of theelongated bore 150 (i.e., the portion of the bore 150 proximate thelocking jaws 148) defines a distal bore 152 that has a smaller diameterthan a proximal bore 154 defined by the remainder of the bore 150. Thesidewall defining the distal bore 152 has an internal geometry thatmatches the external geometry of the drive spline 126. Such acomplimentary feature enhances the rotational stability of the extensiontool 120 as it drives the distal reamer 90.

The drive shaft 122 also includes a locking assembly 156. The lockingassembly 156 includes a locking lever 158 that is pivotally coupled tothe shaft body 132 via a pivot pin 160. One end of a spring link 162 iscoupled to the locking lever 158, with its other end being coupled tothe proximal end 164 of a spline shaft 166. The drive spline 126 isformed in the distal end 168 of the spline shaft 166. The drive spline126 is positionable between an extended or locked position (as shown inFIG. 13) in which the drive spline 126 extends out of the distal end ofthe elongated tip 142 and a retracted or unlocked position in which thedrive spline 162 is retracted into the distal bore 152 of the elongatedtip 142 to a location that is proximal of the locking jaws 148.

To secure the extension tool 120 to the distal reamer 90, the lockingjaws 148 are inserted through the open ends of the locking slots 106 ofthe distal reamer's drive connector 102 and thereafter rotated. Thedrive spline 126 is then positioned in its extended (i.e., locked)position in which it is received in the distal reamer's female drivesocket 108 to secure the extension tool 120 to the distal reamer 90.

By virtue of being coupled to the spline shaft 166 via the spring link162, the locking lever 158 is operable to move the drive spline 126between its extended (i.e., locked) position and its retracted (i.e.,unlocked) position. Namely, when the locking lever 158 is positioned inits locked position (as shown in FIG. 13), the drive spline ispositioned in its extended (i.e., locked) position. However, when thelocking lever 158 is pulled downwardly (in the orientation of FIG. 13)so as to pivot about the pivot pin 160, the spring link 162 and hencethe spline shaft 166 are urged to the right (in the orientation of FIG.13) so as to relieve tension from the spring link 162 and position thedrive spline 126 in its retracted (i.e., unlocked) position.

The extension tool 120 includes a number of colored depth marks 172,174, 176, 178 formed on its elongated tip 142. Like the depth marks 72,74, 76, 78 of the starter reamer 60, each of the colored depth marks172, 174, 176, 178 corresponds to the standard head center of one of thevarious proximal body components 12. For example, the proximal bodycomponent 12 may be provided in four different superior/inferiorlengths—75 mm, 85 mm, 95 mm, and 105 mm In the exemplary embodimentdescribed herein, the depth mark 172 is blue and corresponds to thelocation of the center of the head of a 75 mm proximal body component12, the depth mark 174 is green and corresponds to the location of thecenter of the head of a 85 mm proximal body component 12, the depth mark176 is yellow and corresponds to the location of the center of the headof a 95 mm proximal body component 12, and the depth mark 178 is red andcorresponds to the location of the center of the head of a 105 mmproximal body component 12. The depth marks 172, 174, 176, 178 may beembodied as grooves engraved in the elongated tip 142, each of which isfilled with an epoxy ink of the corresponding color. During a surgicalprocedure, the extension tool 120 is advanced deeper into theintramedullary canal 22 of the patient's femur 20 until the desireddepth mark aligns with the tip 82 of the greater trochanter 84 (see FIG.45). In such a way, over reaming of the distal end of the canal 22 isavoided if the extension tool 120 is not driven beyond the appropriatecolored depth mark 172, 174, 176, 178.

The extension tool 120 is configured to mate with any of the variousconfigurations of the distal reamer 90. In other words, each of thevarious configurations of the distal reamers 90 is compatible with theextension tool 120.

The metallic components of the extension tool 120 (e.g., the variouscomponents of the drive shaft 126, the distal tip 142, et cetera) may beconstructed from a medical-grade metal such as stainless steel, cobaltchrome, or titanium, although other metals or alloys may be used.Moreover, in some embodiments, rigid polymers such aspolyetheretherketone (PEEK) may also be used. The sleeve 138 may beconstructed from similar metals or from a polymer such as delrin.

Referring now to FIGS. 14-20, there is shown a proximal trial instrument180. The proximal trial instrument 180 is modular and, as a result, isembodied as two separate components—a trial shaft 182 and a trial neck184. Like the other instruments and implants described herein, thecomponents of the proximal trial instrument 180 (i.e., the trial shaft182 and the trial neck 184) may be provided in a number of differentsizes. For example, in the illustrative embodiment described herein, thetrial shaft 182 may be embodied in four different lengths (e.g., 75 mm,85 mm, 95 mm, or 105 mm) so as to, when assembled to the distal reamer90 or the distal stem component 14, mimic a 75 mm, 85 mm, 95 mm, or 105mm proximal body component 12. In the illustrative embodiment describedherein, the trial neck 184 may be provided in two different offsetsizes—45 mm and 40 mm The various configurations of the trial shaft 182and the trial neck 184 may be mixed and matched to produce trials ofdifferent sizes. Such a modular instrument significantly reduces thenumber of instruments needed to perform the associated surgicalprocedure. For example, some prior art trial instrument sets included 12different proximal trial instruments, whereas the illustrative systemdescribed herein has six instruments (four trial shafts and two trialnecks).

As can be seen in FIGS. 14-17, the trial shaft 182 includes a body 186having an elongated bore 188 extending therethrough. A locking screw 190is captured in the bore 188. A hex drive head 192 is formed in theproximal end of the locking screw 190, with a number of locking threads194 being formed in its opposite, distal end. The threads 194 are sizedto be received into the lower threads 42 of the distal stem component 14and the threads 112 of the distal reamer 90. As such, in theillustrative embodiment described herein, the threads 194 of the lockingscrew 190 are M6 size threads. As can be seen in the perspective view ofFIG. 14 and the cross-sectional view of FIG. 17, the drive head 192 ofthe locking screw 190 is captured in a bearing 196 and positioned in arecess 198 formed in the proximal end of the trial shaft's body 186.

The body 186 of the trial shaft 182 is generally cylindrical in shape.The proximal end 202 of the body 186 defines a stem 204 to receive thetrial neck 184. A shoulder 206 is formed in the body 186. The trial neck184 slides down the stem 204 and is supported by the shoulder 206. Ascan be seen in FIGS. 14-16, the stem 204 has a splined surface 208formed therein. As will be described in more detail below, the splinedsurface 208 is engaged by a locking pawl 244 of the trial neck 184 (seeFIG. 18) to lock the trial neck 184 into a desired orientation or“version” (i.e., rotational angle) relative to the trial shaft 182.

As can be seen in FIGS. 14-16, an alignment flat 210 is formed in thetrial shaft's body 186. The flat 210 is formed near the body's distalend 212. The alignment flat 210 is embodied as a flat, shallow slot. Theflat 210 facilitates insertion of the proximal trial instrument 180during a surgical procedure.

The trial shaft 182 also includes an alignment key 214 in the form of,for example, a rib that extends outwardly from the distal end 212 of thebody 186. The long axis of the alignment key 214 extends in thesuperior/inferior direction. The alignment key 214 is configured to matewith the keyway 46 formed in the superior surface of the body 38 of thedistal stem component 14 (see FIG. 4). In the exemplary embodimentdescribed herein, the cross-sectional shape of the alignment key 214 islobe shaped to compliment the shape of the stem component's keyway 46.

As shown in FIGS. 18-20, the trial neck 184 includes a body 224 having aneck 226 extending medially therefrom. A trial head (not shown) is taperfit or otherwise secured to the neck 226. The body 224 also has a bore228 formed therein. The bore 228 extends in the superior/inferiordirection through the lateral portion of the body 224. The proximal stem204 of the trial shaft 182 is received into the bore 228 of the trialneck 184. The trial neck 184 slides down the stem 204 of the trial shaft182 until an inferior surface 230 of the trial neck's body 224 contactsthe shoulder 206 formed in the body 186 of the trial shaft (see FIGS.14-17).

The superior surface of the body 224 of the trial neck 184 has acountersunk cavity 232 formed therein. The inferior side of thecountersunk cavity 232 opens into a locking recess 234. The cavity 232and the recess 234 house a locking mechanism 236. The locking mechanism236 includes a friction clamp 238 and a locking screw 240. A hex drivehead 242 is formed in the proximal end of the locking screw 240. Whenthe trial neck 184 is positioned on the trial shaft 182, the lockingmechanism 236 may used to lock the trial neck 184 into a desiredorientation or “version” (i.e., rotational angle) relative to the trialshaft 182. In particular, when the locking screw 240 is tightened by useof a hex driver (such as the one shown in FIG. 56), the friction clamp238 clamps onto or otherwise engages the outer surface of the stem 204of the trial shaft 182 thereby preventing the trial neck 184 fromrotating relative to the trial shaft 182. As can be seen in FIG. 18, thefriction claim 238 has a locking pawl 244 formed therein. When thelocking screw 240 is tightened by use of a hex driver 512 (such as theone shown in FIG. 56), the locking pawl 244 is urged into positioned inone of the grooves of the splined surface 208 of the trial shaft 182.The locking pawl 244 contacts the sidewalls forming the groove of thesplined surface 208 thereby preventing the trial neck 184 from rotatingrelative to the trial shaft 182. When the locking screw 240 is loosenedwith the hex driver, the friction clamp 238 disengages the stem 204 ofthe trial shaft 182 thereby allowing the trial neck 184 to rotate freelyabout the trial shaft 182.

The trial shaft 182 and the trial neck 184 of the proximal trialinstrument 180 may be constructed from a medical-grade metal such asstainless steel, cobalt chrome, or titanium, although other metals oralloys may be used. Moreover, in some embodiments, rigid polymers suchas polyetheretherketone (PEEK) may also be used.

Referring now to FIGS. 21-23, there is shown a reamer guide shaft 250.The reamer guide shaft 250 may be secured to the distal stem component14 or the distal reamer 90 positioned in the intramedullary canal 22 ofthe patient's femur 20 to guide a surgeon's advancement of a finishingrasp 290 (see FIGS. 24 and 25) or proximal reamer 390 (see FIGS. 30-32).The reamer guide shaft 250 includes a body 252 having an elongated bore254 extending therethrough. A locking screw 256 is captured in the bore254. A hex drive socket 258 is formed in the proximal end of the lockingscrew 256, with a number of locking threads 260 being formed in itsopposite, distal end. As will be described below in greater detail, ahex driver may be inserted into the hex drive socket 258 and rotated totighten the reamer guide shaft 250 to the distal stem component 14 orthe distal reamer 90. The locking screw's threads 260 are sized to bereceived into the lower threads 42 of the distal stem component 14 andthe threads 112 of the distal reamer 90. As such, in the illustrativeembodiment described herein, the threads 260 of the locking screw 256are M6 size threads.

The distal end 262 of the body 252 of the reamer guide shaft 250 has analignment flat 264 formed therein. The alignment flat 264 is embodied asa flat, shallow slot. The alignment flat 264 is sized and shaped toclosely complement the size and shape of the alignment key 44 extendingsuperiorly from the superior surface of the body 38 of the distal stemcomponent 14. As mentioned above, the alignment key 44 aligns with theapex of the distal stem component 14. During attachment of the reamerguide shaft 250 to the distal stem component 14, the alignment key 44abuts into contact with the alignment flat 264 formed in the reamerguide shaft's body 252.

Like the trial shaft 182 of the proximal trial instrument 180, thereamer guide shaft 250 also includes an alignment key 284 in the formof, for example, a rib that extends outwardly from the distal end 262 ofthe body 252. The long axis of the alignment key 284 extends in thesuperior/inferior direction. The alignment key 284 is configured to matewith the keyway 46 formed in the superior surface of the body 38 of thedistal stem component 14 (see FIG. 4). In the exemplary embodimentdescribed herein, the cross-sectional shape of the alignment key 284 islobe shaped to compliment the shape of the stem component's keyway 46.

The reamer guide shaft 250 includes a number of colored depth marks 272,274, 276, 278 formed on its body 252. Like the depth marks 72, 74, 76,78 of the starter reamer 60 and the depth marks 172, 174, 76, 178 of theextension tool 120, each of the colored depth marks 272, 274, 276, 278corresponds to the standard head center of one of the various proximalbody components 12. For example, as described above, the proximal bodycomponent 12 may be provided in four different superior/inferiorlengths—75 mm, 85 mm, 95 mm, and 105 mm In the exemplary embodimentdescribed herein, the depth mark 272 is blue and corresponds to thelocation of the center of the head of a 75 mm proximal body component12, the depth mark 274 is green and corresponds to the location of thecenter of the head of a 85 mm proximal body component 12, the depth mark276 is yellow and corresponds to the location of the center of the headof a 95 mm proximal body component 12, and the depth mark 278 is red andcorresponds to the location of the center of the head of a 105 mmproximal body component 12. The depth marks 272, 274, 276, 278 may beembodied as grooves engraved in the body 252 of the reamer guide shaft250, each of which is filled with an epoxy ink of the correspondingcolor.

The reamer guide shaft 250 also includes another colored mark 280 formednear its proximal end. As can be seen in FIGS. 21 and 22, the coloredmark 280 is formed in the outer surface of the reamer guide shaft's body252. Like the colored depth marks 272, 274, 276, 278, the colored mark280 may be embodied as a groove that is engraved in the reamer guideshaft's body 252 and filled with an epoxy ink of a predetermined color,or, alternatively, may be embodied as a laser mark. In the illustrativeembodiment described herein, the colored mark 280 is black. As will bedescribed below in greater detail, the colored mark 280 allows a surgeonto visually confirm that proper seating height has been achieved byobserving the colored mark 280 through the window 314 formed in thefinishing rasp 290 (see FIGS. 24 and 25) or the window 414 formed in theproximal reamer 390 (see FIGS. 30-32). In particular, during a surgicalprocedure, the finishing rasp 290 (see FIGS. 24 and 25) or proximalreamer 390 (see FIGS. 30-32) is advanced deeper into the intramedullarycanal 22 of the patient's femur 20 until the colored mark 280 is visiblethrough a window 314 formed in the finishing rasp 290 (see FIGS. 24 and25) or a window 414 formed in the proximal reamer 390 (see FIGS. 30-32),respectively. In such a way, over rasping or over reaming of theintramedullary canal 22 is avoided.

The reamer guide shaft 250 may be constructed from a medical-grade metalsuch as stainless steel, cobalt chrome, or titanium, although othermetals or alloys may be used. Moreover, in some embodiments, rigidpolymers such as polyetheretherketone (PEEK) may also be used.

Referring now to FIGS. 24 and 25, the finishing rasp 290 is shown inmore detail. The finishing rasp 290 is used in the surgical preparationof the femur 20 of certain patients. For example, when implanting boweddistal stem components 14 having relatively small diameters (e.g., 14-20mm) in patients who do not present a large proximal deformity, it may benecessary to utilize the finishing rasp 290. The finishing rasp 290removes additional bone to facilitate the proper seating of a boweddistal stem component 14.

Like the other instruments and implants described herein, the finishingrasp 290 may be provided in a number of different sizes. For example,finishing rasp 290 may be provided in various diameters to accommodatethe different diameters of the various different distal stem components14. In one illustrative embodiment, the stem component 14 may beprovided in 1 mm diameter increments ranging from 14 to 31 mm In such acase, the finishing rasp 290 may be provided in similar sizes.

The finishing rasp 290 includes an elongated shaft 292 having a handle294 secured to its proximal end 296. The finishing rasp 290 alsoincludes a cutting head 298 secured to the opposite, distal end 302 ofthe shaft 292. The cutting head 298 of the finishing rasp 290 is arcuatein shape and includes a plurality of cutting teeth 304 on its two outersides. The cutting teeth 304 extend longitudinally along the length ofthe cutting head 298. When the finishing rasp 290 is advanced withoscillating motion, the cutting teeth 304 of the finishing rasp 290abrade or otherwise cut the bone tissue of the femur 20 in twodirections thereby gradually creating a notch possessing the geometry(i.e., the shape) required to accept a bowed distal stem component 14.

As can be seen in FIG. 25, the handle 294 is positioned on the shaft 292of the finishing rasp 290 such that one end of the handle 294 is longerthan the other. This provides a visual reference to the surgeon as tothe location of the cutting head 298. Namely, the cutting head 298 islocated on the same side of the shaft 292 as the short side of thehandle 294. In doing so, the short side of the handle 294 provides thesurgeon with a visual reference as to where the cutting head 298 islocated during use of the finishing rasp 290 This allows the cuttinghead 298 to be aligned 180° from the anticipated location of the distalstem component's apex.

The shaft 292 of the finishing rasp 290 has a blind guide bore 306formed therein. As can be seen in the cross sectional view of FIG. 25,the distal end 308 of the guide bore 306 is defined in (i.e., opensthrough) the distal end 302 of the shaft 292 of the finishing rasp 290at a location proximate to the cutting head 298. As noted above, thecutting head 298 is generally arcuate in shape with its concave sidefacing the central axis of the shaft 292. Such a shape providesclearance for the reamer guide shaft 250 to enter the guide bore 306.

The opposite, proximal end 310 of the guide bore 306 is located in therasp's elongated shaft 292 at a location between its proximal end 296and its distal end 302. The proximal end 310 of the guide bore 306 islocated on the proximal side of the middle of the shaft 292 near wherethe shaft 292 tapers down to its smaller diameter that is secured to thehandle 294. The center line of the guide bore 306 and the longitudinalaxis of the finishing rasp 290 lie on the same line.

A depth stop 312 is located in the proximal end 310 of the guide bore306. The depth stop 312 bottoms out on the superior surface 282 of thedrive socket 258 of the reamer guide shaft's locking screw 256 (seeFIGS. 21-23) when the finishing rasp 290 is fully seated. In theillustrative embodiment described herein, the depth stop 312 is embodiedas a dowel pin welded into a bore formed in the rasp's shaft 292 at anangle transverse to its longitudinal axis. It should be appreciated thatother configurations of depth stops may be used, includingconfigurations integral to the rasp's shaft 292.

As can be seen in FIGS. 24 and 25, a number of slotted openings or“viewing windows” 314 are defined in the sidewall 316 of the rasp'sshaft 292 that defines the guide bore 306. The viewing windows 314 allowthe surgeon to visualize the reamer guide shaft 250 as it is received inthe guide bore 306. In doing so, the surgeon can visually confirm thatproper seating of the finishing rasp 290 has been achieved by observingthe colored mark 280 of the reamer guide shaft 250 through the viewingwindows 314 formed in the finishing rasp 290. Specifically, as can beseen in the elevation view of FIG. 24, the outer surface of the rasp'sshaft 292 has colored mark 318 formed therein. The colored mark 318extends around the outer circumference of the shaft 292 and intersectsthe viewing windows 314. Like the colored mark 280 of the reamer guideshaft 250, the colored mark 318 may be embodied as a groove that isengraved in the outer surface of the rasp's shaft 292 and filled with anepoxy ink of a predetermined color, or, alternatively, may be embodiedas a laser mark. In the illustrative embodiment described herein, thecolored mark 318 is black. The surgeon may visually confirm that properseating of the finishing rasp 290 has been achieved when the coloredmark 280 of the reamer guide shaft 250 (which is visible through theviewing windows 314) aligns with the colored mark 318 of the finishingrasp 290.

In the illustrative embodiment described herein, the finishing rasp 290is designed as a finishing tool that removes modest amounts of bonetissue. As such, unlike the other instruments described herein, thehandle 294 is irremovably secured to the proximal end 296 of the rasp'sshaft 292, for example by welding. Such an arrangement prevents thefinishing rasp 290 from being coupled to a power tool. In otherarrangements, it may be desirable to implement a powered version of arasp. In such a case, a removable handle, such as the manual handle 80of FIG. 8 may be employed.

The finishing rasp 290 may be constructed from a medical-grade metalsuch as stainless steel, cobalt chrome, or titanium, although othermetals or alloys may be used. Moreover, in some embodiments, rigidpolymers such as polyetheretherketone (PEEK) may also be used.

Referring now to FIGS. 26 and 27, there is shown a stem insertion tool330. The stem insertion tool 330 may be secured to the distal stemcomponent 14 to facilitate implantation of the distal stem component 14into the intramedullary canal 22 of the patient's femur 20. The steminsertion tool 330 includes a body 332 having an elongated bore 334extending therethrough. A sleeve 336 is positioned around the insertiontool's body 332. The sleeve 336 is immovably coupled to the outersurface of the insertion tool's body 332, such as by, for example,overmolding. The sleeve 336 functions as a grip for allowing the surgeonto hold the stem insertion tool during implantation of the distal stemcomponent 14.

A locking rod 338 is captured in the bore 334. A knob 340 is secured tothe proximal end of the locking rod 338. In addition to being used tosecure the stem insertion tool 330 to the distal stem component 14, theknob 340 is also used as an impact surface. Namely, the surgeon strikesthe superior surface 342 of the knob 340 to drive the distal stemcomponent 14 into the bone tissue within the intramedullary canal 22 ofthe patient's femur 20. As can be seen in FIGS. 26 and 27, the knob 340has a number of holes 362 formed therein. A rod or other type of handle(not shown) may be inserted into the holes 362 to increase the surgeon'sleverage during rotation of the knob 340.

As can be seen in the cross section of FIG. 27, a set of internalthreads 344 formed in the body 332 within the bore 334 and a set ofexternal threads 358 on the locking rod 338 allow the locking rod 338 tobe maintained with the bore 334 while also allowing the stem insertiontool 330 to be disassembled for cleaning between uses.

The locking rod 338 has a set of locking threads 346 formed in itsdistal end. The threads 346 are sized to be received into the upperthreads 40 of the distal stem component 14 (see FIG. 6). As alluded toabove, the upper threads 40 are used to couple the distal stem component14 to the stem insertion tool 330 and any other surgical instrument thatis impacted during use thereof. As such, a set of threads that are notused in assembly of the locking bolt 504 to the femoral prosthesis 10(i.e., the upper threads 40) are subjected to the loads associated withimpaction of the stem insertion tool 330 by the surgeon. In doing so,the set of threads used in assembly of the locking bolt 504 to thefemoral prosthesis 10 (i.e., the lower threads 42), are not subjected tothe loads associated with impaction of the stem insertion tool 330 bythe surgeon. Such “thread preservation” ensures the stem component'sthreads that received the locking bolt 504 (i.e., the lower threads 42)are unharmed by the stem insertion process. In other words, by notsubjecting the lower threads 42 to surgical instruments that areimpacted during implantation of the femoral prosthesis 10, the threadsultimately used to secure the prosthesis's locking bolt 504 (i.e., thelower threads 42) are protected from damage during the surgicalprocedure. As noted above, the upper threads 40 of the distal stemcomponent 14 are M8 size threads, whereas the lower threads 42 are M6size threads. As such, the locking threads 346 of the insertion tool 330are M8 size threads. By being a larger thread size (e.g., M8 vs. M6),the locking threads 346 of the stem insertion tool 330 cannotinadvertently be driven into the lower threads 42 of the distal stemcomponent 14.

The distal end 348 of the body 332 of the stem insertion tool 330 has analignment notch 350 formed therein. The alignment notch 350 is sized andshaped to closely complement the size and shape of the alignment key 44extending superiorly from the superior surface of the body 38 of thedistal stem component 14 (see FIG. 4). As mentioned above, the alignmentkey 44 aligns with the apex of the distal stem component 14. Duringattachment of the stem insertion tool 330 to the distal stem component14, the alignment key 44 is received into the alignment notch 350 formedin the insertion tool's body 332.

The distal end 348 of the body 332 of the stem insertion tool 330 has anretaining flange 360 secured thereto. The retaining flange 360 extendsaround a portion of the outer periphery of the body 332. As will bediscussed below in greater detail, the retaining flange 360 prevents thetaper-protecting sleeve 380 from inadvertently being dislodged from thedistal stem component 14 during use of the stem insertion tool 330.

A pair of impact wings 352 extend outwardly from the proximal end 354 ofthe body 332 of the stem insertion tool 330. In the illustrativeembodiment described herein, the impact wings 352 are integrally formedwith the body 332 of the insertion tool 330. As described above, duringimplantation of the distal stem component 14, the surgeon strikes thesuperior surface 342 of the knob 340 to drive the distal stem component14 into the bone tissue within the intramedullary canal 22 of thepatient's femur 20 (i.e., drive the distal stem component 14 in theinferior direction). If the surgeon needs to reposition or remove thedistal stem component 14 from the intramedullary canal 22 of thepatient's femur 20 (with the distal stem component 14 still securedthereto), the surgeon strikes the underside 356 of the impact wings 352(i.e., the inferior side of the impact wings 352). Such an impact drivesthe stem insertion tool 330 (and hence the distal stem component 14attached thereto) in the superior direction thereby allowing it to beremoved from, or repositioned within, the intramedullary canal 22 of thepatient's femur 20.

Once the surgeon has positioned the distal stem component 14 in theintramedullary canal 22 of the patient's femur 20, the stem insertiontool 330 may be disconnected from the distal stem component 14 byrotating the knob 340 to release the locking threads 346 from the upperthreads 40 of the distal stem component 14.

The stem insertion tool 330 includes a number of colored depth marks372, 374, 376, 378 formed on its body 332. Like the depth marks 72, 74,76, 78 of the starter reamer 60, the depth marks 172, 174, 176, 178 ofthe extension tool 120, and the depth marks 272, 274, 276, 278 of thereamer guide shaft 250, each of the colored depth marks 372, 374, 376,378 corresponds to the standard head center of one of the variousproximal body components 12. For example, as described above, theproximal body component 12 may be provided in four differentsuperior/inferior lengths—75 mm, 85 mm, 95 mm, and 105 mm In theexemplary embodiment described herein, the depth mark 372 is blue andcorresponds to the location of the center of the head of a 75 mmproximal body component 12, the depth mark 374 is green and correspondsto the location of the center of the head of a 85 mm proximal bodycomponent 12, the depth mark 376 is yellow and corresponds to thelocation of the center of the head of a 95 mm proximal body component12, and the depth mark 378 is red and corresponds to the location of thecenter of the head of a 105 mm proximal body component 12. The depthmarks 372, 374, 376, 378 may be embodied as grooves engraved in the body332 of the stem insertion tool 330, each of which is filled with anepoxy ink of the corresponding color. During a surgical procedure, thestem insertion tool 330, with the distal stem component 14 securedthereto, is advanced deeper into the intramedullary canal 22 of thepatient's femur 20 until the desired depth mark aligns with the tip 82of the greater trochanter 84 (see FIG. 51). In such a way, the desiredimplant depth of the distal stem component 14 can be achieved.

The metallic components of the stem insertion tool 330 (e.g., theinsertion tool's body 332, locking rod 338, et cetera) may beconstructed from a medical-grade metal such as stainless steel, cobaltchrome, or titanium, although other metals or alloys may be used.Moreover, in some embodiments, rigid polymers such aspolyetheretherketone (PEEK) may also be used. The grip 336 may beconstructed from a polymer such as silicone.

Referring now to FIGS. 28 and 29, there is shown a taper-protectingsleeve 380. In the illustrative embodiment described herein, thetaper-protecting sleeve 380 is packaged with the distal stem component14. The taper-protecting sleeve 380 is installed on the tapered post 30formed in the superior end of the distal stem component 14 (see FIGS.50-52). As described above, the tapered post 30 of the distal stemcomponent 14 is received into the tapered bore 28 of the proximal bodycomponent 12 with an applied compressive force taper locking the tapersof the two components together. The taper-protecting sleeve 380 reduces,or even eliminates, potential damage to the outer surfaces of thetapered post 30 of the distal stem component 14 during the surgicalprocess thereby enhancing the integrity of the taper lock between thedistal stem component 14 and the proximal body component 12. Thetaper-protecting sleeve 380 includes a cannulated body 382 having anelongated bore 384 extending therethrough.

A beveled edge 386 located in the elongated bore 384 divides thetaper-protecting sleeve 380 into a superior portion and an inferiorportion. When the taper-protecting sleeve 380 is assembled to the body38 of the distal stem component 14, the proximal start of the bevelededge 386 of the taper-protecting sleeve 380 engages the proximal surfaceof the tapered post 30 of the distal stem component 14. During suchassembly, the portion of the body 382 of the taper-protecting sleeve 380that defines the distal end of the elongated bore 384 also engages thedistal surface of the tapered post 30 of the distal stem component 14.As such, the superior portion of the taper-protecting sleeve 380 sitsabove the superior surface of the body 38 of the distal stem component14. In such a way, the superior portion of the taper-protecting sleeve380 functions as a grip to be grabbed or otherwise engaged by forceps orother instrument to facilitate removal of the taper-protecting sleeve380 after its use. The outer surface of the superior portion of thetaper-protecting sleeve 380 includes a number of ribs 388. The ribs 388provide an engagement surface for the forceps during removal of thetaper-protecting sleeve 380.

As alluded to above, the taper-protecting sleeve 380 is packaged withthe distal stem component 14. As a result, it is provided to the surgeonin a sterile package, along with the distal stem component 14. Thetaper-protecting sleeve 380 may be pre-installed on the distal stemcomponent 14 and, as a result, provided to the surgeon in the samesterile package as the distal stem component 14. Alternatively, thetaper-protecting sleeve 380 may be provided to the surgeon in a separatesterile package from the sterile package that includes the distal stemcomponent 14. In such a case, the surgeon removes the taper-protectingsleeve 380 from the separate package and installs it onto the distalstem component 14 prior to implantation thereof.

The taper-protecting sleeve 380 may be made of any suitable material,including medical-grade polymeric material. Examples of such polymericmaterials include polyethylene such as ultrahigh molecular weightpolyethylene (UHMWPE) or polyetheretherketone (PEEK). In such aconfiguration, the taper-protecting sleeve 380 may be used as adisposable instrument.

Referring now to FIGS. 30-32, there is shown the proximal reamer 390 inmore detail. The proximal reamer 390 is used to surgically prepare thepatient's femur 20 for implantation of the proximal body component 12.As will be discussed below in regard to FIG. 48, operation of theproximal reamer 390 is performed over the distal stem component 14 toensure final seating height and stem biomechanics. In some embodiments,operation of the proximal reamer 390 may also be performed over thedistal reamer 90 when the distal reamer 90 is positioned in thepatient's femur 20.

Like the other instruments and implants described herein, the proximalreamer 390 may be provided in a number of different sizes. For example,proximal reamer 390 may be provided in various diameters to accommodatethe various different configurations of the proximal body components 12.In one illustrative embodiment, the proximal reamer 390 may be providedwith 20 mm, 24 mm, and 28 mm cutting head diameters.

The proximal reamer 390 includes an elongated shaft 392 having aproximal end 394 that fits into the chuck of a rotary power tool 86 (seeFIG. 53) or a manual handle 80 (see FIG. 8). The proximal reamer 390also includes a cutting head 396 located at the opposite, distal end 398of the shaft 392. The cutting head 396 of the proximal reamer 390includes a plurality of helical cutting flutes 402. When the proximalreamer 390 is positioned in the patient's femur 20 and rotated, thecutting flutes 402 ream or otherwise cut the bone tissue of the femur 20to form a surgically-created cavity to accommodate the geometry of theproximal body component 12. The cutting head 396 is generallycylindrical or conical in shape. The center line of the cutting head 396and the longitudinal axis of the proximal reamer 390 lie on the sameline. As can be seen in FIGS. 30 and 31, the lead cutting edge 404 ofthe cutting flutes 402 extends beyond the distal end 398 of the shaft392.

The shaft 392 of the proximal reamer 390 has a blind guide bore 406formed therein. As can be seen in the cross sectional view of FIG. 32,the distal end 408 of the guide bore 406 is defined in (i.e., opensthrough) the distal end 398 of the shaft 392 of the proximal reamer 390at a location proximate to the cutting head 396. The opposite, proximalend 410 of the guide bore 406 is located near the proximal end 394 ofthe reamer's elongated shaft 392. The center line of the guide bore 406and the longitudinal axis of the proximal reamer 390 lie on the sameline.

A depth stop 412 is located in the proximal end 410 of the guide bore406. The depth stop 412 bottoms out on the superior surface 282 of thedrive socket 258 of the locking screw 256 of the reamer guide shaft 250(see FIGS. 22 and 23) when the proximal reamer 390 is fully seated. Inthe illustrative embodiment described herein, the depth stop 412 isembodied as a dowel pin welded into a bore formed in the reamer's shaft392 at an angle transverse to its longitudinal axis. It should beappreciated that other configurations of depth stops may be used,including configurations integral to the reamer's shaft 392.

As can be seen in FIGS. 30-32, a number of slotted openings or “viewingwindows” 414 are defined in sidewall 416 of the reamer's shaft 392 thatdefines the guide bore 406. The viewing windows 414 allow the surgeon tovisualize the reamer guide shaft 250 as it is received in the guide bore406. In doing so, the surgeon can visually confirm that proper seatingof the proximal reamer 390 has been achieved by observing the coloredmark 280 of the reamer guide shaft 250 through the viewing windows 414formed in the proximal reamer 390. Specifically, as can be seen in theelevation view of FIG. 30, the outer surface of the reamer's shaft 392has colored mark 418 formed therein. The colored mark 418 extends aroundthe outer circumference of the shaft 392 and intersects the viewingwindows 414. Like the colored mark 280 of the reamer guide shaft 250,the colored mark 418 may be embodied as a groove that is engraved in theouter surface of the reamer's shaft 392 and filled with an epoxy ink ofa predetermined color, or, alternatively, may be embodied as a lasermark. In the illustrative embodiment described herein, the colored mark418 is black. The surgeon may visually confirm that proper seating ofthe proximal reamer 390 has been achieved when the colored mark 280 ofthe reamer guide shaft 250 (which is visible through the viewing windows414) aligns with the colored mark 418 of the proximal reamer 390.

A male connector 420 is formed in the proximal end 394 of the reamer'sshaft 392. The connector 420 fits into the chuck of a rotary power tool86 (see FIG. 53) or a manual handle 80 (see FIG. 8) to couple theproximal reamer 390 to a rotary drive source.

The proximal reamer 390 includes a number of colored depth marks 422,424, 426, 428 formed on its body 392. Like the depth marks 72, 74, 76,78 of the starter reamer 60, the depth marks 172, 174, 176, 178 of theextension tool 120, the depth marks 272, 274, 276, 278 of the reamerguide shaft 250, and the depth marks 372, 374, 376, 378 of the steminsertion tool 330, each of the colored depth marks 422, 424, 426, 428corresponds to the standard head center of one of the various proximalbody components 12. For example, as described above, the proximal bodycomponent 12 may be provided in four different superior/inferiorlengths—75 mm, 85 mm, 95 mm, and 105 mm In the exemplary embodimentdescribed herein, the depth mark 422 is blue and corresponds to thelocation of the center of the head of a 75 mm proximal body component12, the depth mark 424 is green and corresponds to the location of thecenter of the head of a 85 mm proximal body component 12, the depth mark426 is yellow and corresponds to the location of the center of the headof a 95 mm proximal body component 12, and the depth mark 428 is red andcorresponds to the location of the center of the head of a 105 mmproximal body component 12. The depth marks 422, 424, 426, 428 may beembodied as grooves engraved in the body 392 of the proximal reamer 390,each of which is filled with an epoxy ink of the corresponding color.

The proximal reamer 390 may be constructed from a medical-grade metalsuch as stainless steel, cobalt chrome, or titanium, although othermetals or alloys may be used.

Referring now to FIGS. 33 and 34, there is shown a trial insertion tool430. The trial insertion tool 430 may be used to clasp the proximaltrial instrument 180 to facilitate its attachment to the distal reamer90 or the distal stem component 14 implanted in the intramedullary canal22 of the patient's femur 20. The trial insertion tool 430 is similar toa pair of surgical scissors or a surgical clamp in that it includes apair of levers 432 pivoted together with a pivot pin 434. A proximal endof each of the levers 432 has a handle or loop 436 secured thereto. Thedistal end of the levers 432 cooperate to form a cylindrically-shapedretention socket 442. The retention socket 442 is sized and shaped toreceive the stem 204 formed in the proximal end 202 of the trial shaft182. In particular, as shown in the elevation view of FIG. 35, theretention socket 442 has a recess 444 formed therein. The recess 444 issized to closely mimic the size of the outer surface of the stem 204 ofthe trial shaft 182 so as to receive it therein. As can also be seen inthe elevation view of FIG. 35, the recess 444 is configured with a“tri-lobe” geometry to ensure that the retention socket 442 firmlyengages the trial shaft 182.

When a surgeon urges the two loops 436 away from one another, the levers432 pivot about the pin 434 and the two halves of the retention socket442 spread slightly away from one another. The stem 204 of the trialshaft 182 may then be advanced into the recess 444 of the retentionsocket 442. Thereafter, the surgeon may squeeze or otherwise urge thetwo loops 436 toward one another thereby causing the levers 432 to pivotabout the pin 434 toward one another. Doing so urges the two halves ofthe retention socket 442 toward one another thereby squeezing the stem204 of the trial shaft 182 so as to retain the trial shaft 182 in theretention socket 442. As can be seen in FIG. 33, each of the levers 432of the trial insertion tool 430 has a number of ratchet teeth 446 formedtherein at a location between the loops 436. The ratchet teeth 446 allowthe surgeon to lock the levers 432 in a position in which the trialshaft 182 is locked in the retention socket 442.

The trial insertion tool 430 may be constructed from a medical-grademetal such as stainless steel, cobalt chrome, or titanium, althoughother metals or alloys may be used.

Referring now to FIGS. 36-39, there is shown a version-replicatinginstrument 460. As will be discussed below in more detail in regard toFIGS. 58-61, the version-replicating instrument 460 may be used toensure that the version of the implanted proximal body component 12replicates the version that was determined by use of the proximal trialinstrument 180 during trialing.

The version-replicating instrument 460 includes an elongated shaft 462having an alignment stem 464 extending from its distal end 466. In theillustrative embodiment described herein, the version-replicatinginstrument 460 is embodied as a monolithic component. Hence, thealignment stem 464 is integrally formed with the elongated shaft 462. Analignment key 468 in the form of, for example, a rib extends outwardlyfrom the alignment stem 464. The longitudinal axis of the alignment key468 extends in the superior/inferior direction. The alignment key 468 isconfigured to mate with the keyway 46 formed in the superior surface ofthe body 38 of the distal stem component 14 (see FIG. 4). In theexemplary embodiment described herein, the cross-sectional shape of thealignment key 468 is lobe shaped to compliment the shape of the stemcomponent's keyway 46. In such a way, the alignment key 468 is identicalto the alignment key 214 formed on the distal end 212 of the trial shaft182 of the proximal trial instrument 180 (see FIGS. 14-16).

As shown in the cross sectional view of FIG. 39, the version-replicatinginstrument's shaft 462 has a countersunk blind hole 470 formed in itsproximal end 472. The shaft's proximal end 472 also has an alignmentslot 474 formed therein. Like the alignment key 468, the longitudinalaxis of the alignment slot 474 extends in the superior/inferiordirection. The proximal end 476 of the alignment slot 474 is open, withits distal end 478 being closed in the shaft 462. As can be seen in thecross sectional view of FIG. 39, the alignment slot 474 opens into thehole 470 formed in the shaft 462.

As can be seen in FIG. 36, the version-replicating instrument'salignment slot 474 is aligned with its alignment key 468. In particular,the longitudinal axis of the alignment slot 474 and the longitudinalaxis of the alignment key lie on the same imaginary line 480.

As will be discussed below in more detail in regard to FIGS. 58-61,during a surgical procedure to taper lock the proximal body component 12to the implanted distal stem component 14, the distal end 212 of thetrial shaft 182 of the proximal trial instrument 180 (see FIGS. 14-16)is inserted into the blind hole 470 formed in the proximal end of theversion-replicating instrument's shaft 462. In doing so, the alignmentkey 214 formed on the trial shaft 182 of the proximal trial instrument180 is received into the alignment slot 474 formed in theversion-replicating instrument's shaft 462.

Like many of the other instruments described herein, theversion-replicating instrument 460 includes a number of colored depthmarks 482, 484, 486, 488 formed on the outer surface of its shaft 462.Unlike the other depth marks described herein (e.g., the depth marks 72,74, 76, 78 of the starter reamer 60, the depth marks 172, 174, 76, 178of the extension tool 120, et cetera), each of the colored depth marks482, 484, 486, 488 does not correspond to the standard head center ofone of the various proximal body components 12, but rather correspondsto the location of the shoulder 52 of the one of the various proximalbody components 12 (see FIG. 2). For example, as described above, theproximal body component 12 may be provided in four differentsuperior/inferior length—75 mm, 85 mm, 95 mm, and 105 mm In theexemplary embodiment described herein, the depth mark 482 is blue andcorresponds to the location of the shoulder 52 of a 75 mm proximal bodycomponent 12, the depth mark 484 is green and corresponds to thelocation of the shoulder 52 of a 85 mm proximal body component 12, thedepth mark 486 is yellow and corresponds to the location of the shoulder52 of a 95 mm proximal body component 12, and the depth mark 488 is redand corresponds to the location of the shoulder 52 of a 105 mm proximalbody component 12. The depth marks 482, 484, 486, 488 may be embodied asgrooves engraved in the shaft 462 of the version-replicating instrument460, each of which is filled with an epoxy ink of the correspondingcolor.

The version-replicating instrument 460 may be constructed from amedical-grade metal such as stainless steel, cobalt chrome, or titanium,although other metals or alloys may be used. Moreover, in someembodiments, rigid polymers such as polyetheretherketone (PEEK) may alsobe used.

Referring now to FIGS. 40-43, there is shown a stem stabilizer 490. Thestem stabilizer 490 may be secured to the proximal body component 12 toprevent the implanted modular femoral prosthesis 10 from rotating duringinstallation of the locking bolt 504 (see FIGS. 64-66). The stemstabilizer 490 includes a body 492 having an elongated bore 494extending therethrough. A drive rod 514 is captured in the bore 494. Asquare-type drive head 496 is formed in the proximal end of the driverod 514, with a drive socket 498 being formed in its opposite, distalend. The drive socket 498 is sized to receive the head 502 of thelocking bolt 504 (see FIG. 64). As such, rotation of the drive head 496of the drive rod 514 causes rotation of the drive socket 498 and hencethe head 502 of the locking bolt 504 positioned therein.

As shown in FIGS. 40 and 42, a handle 506 extends upwardly away from thebody 492 of the stem stabilizer 490. A surgeon holds onto the handle 506to prevent rotation of the stem stabilizer 490 (and hence correspondingrotation of the proximal body component 12) during installation of thelocking bolt 504. As can be seen in FIGS. 40 and 42, the handle 506 hasa knurled outer surface. Such a textured surface increases the surgeon'sability to grip the handle 506, particularly in the presence of thefluids commonly present during a surgical procedure.

A fork 508 extends away from the body 492 of the stem stabilizer 490 ina generally downward direction. As will be discussed below in regard toFIGS. 64-66, the elongated neck 16 of the proximal body component 12 iscaptured between the tines 510 of the fork 508 when the stem stabilizer490 is installed on the implanted modular femoral prosthesis 10. Assuch, when the surgeon prevents the stem stabilizer from rotating duringinstallation of the locking bolt 504, the implanted modular femoralprosthesis 10 is likewise prevented from rotating by virtue of havingthe elongated neck 16 of the proximal body component 12 captured in thefork 508. The tines 510 of the fork 508 may be coated or otherwisecovered with a non-metal (e.g., radel) cap to prevent damage to theelongated neck 16 of the proximal body component 12.

The stem stabilizer 490 may be constructed from a medical-grade metalsuch as stainless steel, cobalt chrome, or titanium, although othermetals or alloys may be used.

Referring now to FIGS. 44-66, there is shown a surgical procedure inwhich the various instruments described herein in regard to FIGS. 7-43are used to surgically prepare the patient's femur 20 for implantationof the femoral prosthesis 10 of FIGS. 1-6. Typically, the femoralprosthesis 10 is being implanted as part of a revision procedure. Assuch, the surgical procedure begins with preoperative planning in which,amongst other things, a CT scan or other type of preoperative image maybe obtained to plan the removal of the existing femoral implant, alongwith placement location and orientation of the revision femoralprosthesis 10. With the preoperative planning complete, the patient'ssoft tissue is dissected and retracted in order to allow access to thehip joint. Full exposure of the patient's existing femoral prosthesis istypically achieved (i.e., the prosthesis that was previously implantedand now being removed and replaced with the femoral prosthesis 10).

Thereafter, the previous femoral implant is removed. In particular, thesurgeon extracts the previous femoral implant thereby leaving an exposedopening in the patient's femur 20 where the previous femoral implant waslocated. The surgeon then prepares the intramedullary canal 22 of thepatient's femur 20 to receive the revision femoral prosthesis 10.Initially, as shown in FIG. 44, the surgeon uses the starter reamer 60to ream the portion of the patient's intramedullary canal 22 into whichthe distal stem component 14 is implanted. To do so, the surgeon insertsthe proximal end 64 of the starter reamer into the chuck of the manualhandle 80 (or, optionally, a rotary power tool 86). The surgeon thenpositions the cutting head 66 of the starter reamer 60 in theintramedullary canal 22 of the patient's femur 20 and thereafter rotatesthe handle 80. Such rotation of the handle causes the cutting flutes 70to ream or otherwise cut the bone tissue of the femur thereby obtainingclear access to the femoral canal. Such access to the intramedullarycanal 22 ensures proper alignment of the components of the revisionfemoral prosthesis 10 during subsequent surgical steps. In theillustrative embodiment described herein, a 140 mm length starter reamer60 may be used to obtain such clear access to the femoral canal prior todistal reaming.

As described above, each of the colored depth marks 72, 74, 76, 78 onthe starter reamer's shank 62 corresponds to the standard head center ofa number of different proximal body components 12. For example, theproximal body component 12 may be provided in four different lengths—75mm, 85 mm, 95 mm, and 105 mm In the illustrative method describedherein, the starter reamer 60 may be seated to the level of the 85 mmproximal body to re-establish the center of rotation of the femoralhead. In doing so, one size proximal body shorter and two longer thenremain to either increase or decrease leg length. As such, the starterreamer 60 is advanced deeper into the intramedullary canal 22 of thepatient's femur 20 until the depth mark 74 (the green depth mark) alignswith the tip 82 of the greater trochanter 84 (see FIG. 44). Havinggained clear access to the intramedullary canal 22 of the patient'sfemur 20, the starter reamer 60 is then removed.

The surgeon next utilizes the distal reamer 90 to ream the portion ofthe patient's intramedullary canal 22 into which the distal stemcomponent 14 is implanted. The distal reamer 90 produces a borepossessing the final geometry (i.e., the shape) required to accept thedistal stem component 14 of the femoral prosthesis 10. Based on thedesired diameter and length of the distal stem component 14 determinedduring a preoperative templating process, the surgeon first selects theappropriate size of the distal reamer 90 to be used. In particular, asdiscussed above, the distal reamer 90 may be provided in four differentlengths—140 mm, 190 mm, 240 mm, and 290 mm—each of which corresponds toone of the available lengths of the distal stem component 14. Suchreamers 90 are provided in 1 mm diameter increments ranging from 14 to31 mm

Depending on the size of the intramedullary canal 22 of the patient'sfemur 20, the surgeon selects and attaches a distal reamer 90 having anappropriately sized diameter and length to the extension tool 120. To doso, the surgeon first pulls downwardly (in the orientation of FIG. 13)on the locking lever 158 of the extension tool 120 so as to position thedrive spline 126 of the extension tool 120 in its retracted (i.e.,unlocked) position. The surgeon then inserts the locking jaws 148 of theextension tool 120 through the open ends of the locking slots 106 of thedistal reamer's drive connector 102. The surgeon then rotates theextension tool 120 such that the locking jaws 148 are captured in thelocking slots 106 of the distal reamer's drive connector 102. Thiscreates axial stability between the extension tool 120 and the selecteddistal reamer 90. The surgeon then moves the locking lever 158 to itslocked position (as shown in FIG. 13) thereby moving the drive spline126 to its extended (i.e., locked) position in which it is received intothe distal reamer's female drive socket 108. This locks the distalreamer 90 to the extension tool 120 thereby creating rotationalstability between the extension tool 120 and the distal reamer 90.

The male connector 134 of the extension tool 120 is then inserted intothe chuck of the rotary power tool 86. As shown in FIG. 45, the surgeonthen inserts the cutting head 96 of the distal reamer 90 into theintramedullary canal 22 of the patient's femur 20 and activates thepower tool 86. The power tool 86 rotates the distal reamer 90 therebycausing its cutting flutes 100 to ream or otherwise cut the bone tissueof the femur 20. The extension tool 120, with the distal reamer 90secured thereto, is advanced deeper into the intramedullary canal 22 ofthe patient's femur 20 until the desired depth mark 172, 174, 176, 178aligns with the tip 82 of the greater trochanter 84.

The initial distal reamer 90 is then removed from the extension tool 120and the reamer 90 with the next larger diameter and/or length is thenattached to the extension tool 120 and the process repeated. The surgeonprogressively reams in diameter and/or length with increasingly largerdistal reamers 90 until engagement with sufficient cortical bone tissueis achieved (known as “good cortical chatter”) and the appropriate depthis obtained.

Thereafter, the surgeon may opt to perform a trial procedure with use ofthe distal reamer 90. In particular, if a large proximal deformityexists and traditional bony landmarks are absent, trialing off thedistal reamer 90 may be conducted to obtain an early indication of leglength and offset, for example. In such a case, the surgeon pulls thelocking lever 158 on the extension tool 120 thereby allowing theextension tool 120 to be decoupled from the distal reamer 90 stillpositioned in the intramedullary canal 22 of the patient's femur 20.Thereafter, as shown in FIG. 46, the surgeon secures the proximal trialinstrument 180 to the distal reamer positioned in the intramedullarycanal 22 of the patient's femur 20. Specifically, the surgeon selects atrial shaft 182 which corresponds to the distal reamer depth that wasreferenced during distal reaming (i.e., based on which depth mark 172,174, 176, 178) was utilized during reaming To insert the trial shaft182, the surgeon uses the trial insertion tool 430. Specifically, thesurgeon urges the two loops 436 of the insertion tool 430 away from oneanother such that the levers 432 pivot about the pin 434 and the twohalves of the retention socket 442 spread slightly away from oneanother. The stem 204 of the trial shaft 182 may then be advanced intothe recess 444 of the retention socket 442. Thereafter, the surgeonsqueezes or otherwise urges the two loops 436 toward one another therebycausing the levers 432 to pivot about the pin 434. Doing so urges thetwo halves of the retention socket 442 toward one another therebysqueezing the stem 204 of the trial shaft 182 so as to retain the trialshaft 182 in the retention socket 442.

The distal end of the trial shaft 182 is then inserted into thecountersunk drive connector 102 formed in the proximal end 94 of thedistal reamer 90. In doing so, the locking threads 194 of the trialshaft 182 are started in the threads 112 of the distal reamer 90. Thesurgeon then inserts a hex driver 512 (such as the one shown in FIG. 56)into the hex drive head 192 of the trial shaft's locking screw 190.Thereafter, the surgeon rotates the hex driver 512 so as to rotate thelocking threads 194 formed in the distal end of the trial shaft'slocking screw 190 thereby driving the trial shaft's threads 194 into thethreads 112 of the distal reamer 90. It should be appreciated that thehex driver 512 may be embodied as a torque limiting hex driver toprevent over tightening of the locking screw 190.

As shown in FIG. 46, the trial neck 184 may be installed on the trialshaft 182 prior to coupling the trial shaft 182 to the distal reamer 90.If it is not installed beforehand, the trial neck 184 may be installedon the trial shaft 182 after the shaft is coupled to the distal reamer90. To do so, the surgeon advances the trial neck 184 such that theproximal stem 204 of the trial shaft 182 is received into the bore 228of the trial neck 184. The trial neck 184 slides down the stem 204 ofthe trial shaft 182 until the inferior surface 230 of the trial neck'sbody 224 contacts the shoulder 206 formed in the body 186 of the trialshaft 182 (see also FIGS. 14-17).

At this point, the trial neck 184 is freely movable relative to thetrial shaft 182. Upon orientating the trial neck 184 in the properversion, it may be secured in the desired position by inserting a manualuniversal hex driver 512 (such as the one shown in FIG. 56) in the hexdrive head 242 formed in the proximal end of the trial neck's lockingscrew 240. The surgeon may then tighten the locking screw 240 byrotating the hex driver 512. By doing so, the locking pawl 244 of thetrial neck's friction clamp 238 is urged into positioned in one of thegrooves of the splined surface 208 of the trial shaft 182. The lockingpawl 244 contacts the sidewalls forming the groove of the splinedsurface 208 thereby preventing the trial neck 184 from rotating relativeto the trial shaft 182. It should be appreciated that the hex driver 512may be embodied as a torque limiting hex driver to prevent overtightening of the locking screw 240.

The surgeon may then install a trial femoral head (not shown) on thetrial neck 184 and perform a trial reduction to confirm appropriate leglength, offset, and component orientation. Once the trial reduction iscomplete, the proximal trial instrument 180 is removed by coupling thetrial insertion tool 430 to the trial shaft 182 in the manner describedabove. The surgeon then inserts the hex driver 512 into the hex drivehead 192 of the trial shaft's locking screw 190 and rotates it in theopposite direction it was rotated during installation thereby rotatingthe locking threads 194 formed in the distal end of the trial shaft'sdrive shaft 122 in a direction which causes them to exit the threads 112of the distal reamer 90. The proximal trial instrument 180 may then beremoved from the distal reamer 90.

When implanting bowed distal stem components 14 having relatively smalldiameters (e.g., 14-20 mm) in patients who do not present a largeproximal deformity, it may be necessary to utilize the finishing rasp290. As shown in FIGS. 48 and 49, the surgeon may use the finishing rasp290 to remove additional bone to facilitate the proper seating of abowed distal stem component 14. To use the finishing rasp 290, thesurgeon first couples the reamer guide shaft 250 to the distal reamer 90that is still positioned in the intramedullary canal 22 of the patient'sfemur 20 (see FIG. 47). To do so, the distal end of the reamer guideshaft 250 is positioned on the proximal end 94 of the distal reamer 90.The surgeon then secures the reamer guide shaft 250 to the distal reamer90 by inserting a manual universal hex driver 512 (such as the one shownin FIG. 56) in the hex drive socket 258 formed in the proximal end ofthe reamer guide shaft's locking screw 256. The surgeon may then rotatethe hex driver to drive the reamer guide shaft's locking screw 256thereby driving its threads 260 into the threads 112 of the distalreamer 90. It should be appreciated that the hex driver 512 may beembodied as a torque limiting hex driver to prevent over tightening ofthe locking screw 256.

The surgeon then selects a finishing rasp 290 that has a diameter thatcorresponds to that diameter of the final distal reamer 90 used duringthe progressive distal reaming operation (such a size also correspondsto the size of the distal stem component 14 that was preoperativelydetermined). The surgeon then positions the finishing rasp 290 such thatthe distal end 308 of its guide bore 306 is located above the proximalend of the reamer guide shaft 250. The finishing rasp 290 is thenadvanced such that the reamer guide shaft 250 enters the guide bore 306of the finishing rasp 290. Once inserted over the reamer guide shaft250, the surgeon uses the handle 294 to oscillate the finishing rasp 290back and forth through 180° of oscillating motion thereby causing thecutting teeth 304 of the finishing rasp 290 to abrade or otherwise cutthe excess bone tissue of the medial cortex in two directions. Thus, anotch possessing the geometry (i.e., the shape) required to accept abowed distal stem component 14 is gradually created and should bepositioned 180° from the planned location of the distal stem component'sapex. The finishing rasp's depth stop 312 bottoms out on the superiorsurface 282 of the drive socket 258 of the reamer guide shaft's lockingscrew 256 (see also FIGS. 22 and 23) when the finishing rasp 290 isfully seated.

During such use of the finishing rasp 290, the rasp's viewing windows314 allow the surgeon to visualize the reamer guide shaft 250 as it isadvanced along the rasp's guide bore 306. In doing so, the surgeon canvisually confirm that proper seating of the finishing rasp 290 has beenachieved by observing the colored mark 280 of the reamer guide shaft 250through the viewing windows 314 formed in the finishing rasp 290.Specifically, the surgeon may visually confirm that proper seating ofthe finishing rasp 290 has been achieved when the colored mark 280 ofthe reamer guide shaft 250 (which is visible through the viewing windows314) aligns with the colored mark 318 of the finishing rasp 290.

Once the rasping operation is complete, the finishing rasp 290 isremoved from the reamer guide shaft 250. The reamer guide shaft 250 isthen itself removed from the distal reamer 90 by inserting the manualuniversal hex driver 512 in the hex drive socket 258 formed in theproximal end of the reamer guide shaft's locking screw 256 and rotatingthe locking screw 256 in the opposite direction it was rotated duringinstallation thereby rotating the locking threads 260 formed in thedistal end of the locking screw 256 in a direction which causes them toexit the threads 112 of the distal reamer 90. The reamer guide shaft 250may then be removed from the distal reamer 90.

The distal reamer may then be removed from the intramedullary canal 22of the patient's femur 20. To do so, the surgeon couples the extensiontool 120 to the distal reamer 90 in the manner described above.Thereafter, the surgeon operates the rotary power tool 86 (or the manualhandle 80) to back the distal reamer 90 out of the intramedullary canal22 of the patient's femur 20.

Once the distal reamer 90 has been removed, the surgeon may then implantthe distal stem component 14. To do so, the surgeon first ensures thetaper-protecting sleeve 380 is installed on the tapered post 30 formedin the superior end of the distal stem component 14. Thetaper-protecting sleeve 380 reduces, or even eliminates, potentialdamage to the outer surfaces of the tapered post 30 of the distal stemcomponent 14 during the subsequent surgical steps thereby enhancing theintegrity of the taper lock between the distal stem component 14 and theproximal body component 12. As alluded to above, the taper-protectingsleeve 380 may be pre-installed on the distal stem component 14 by themanufacturer and, as a result, require no additional attention by thesurgeon. Alternatively, if the taper-protecting sleeve 380 is providedto the surgeon in a separate sterile package, the surgeon removes thetaper-protecting sleeve 380 from the separate package and installs itonto the distal stem component 14 prior to implantation thereof.

Thereafter, as shown in FIG. 50, the distal stem component 14 is coupledto the stem insertion tool 330. The surgeon aligns the stem insertiontool's alignment notch 350 with the alignment key 44 extendingsuperiorly from the superior surface of the body 38 of the distal stemcomponent 14. As described above, the alignment key 44 aligns with theapex of the distal stem component 14. The distal stem component 14 ispositioned relative to the stem insertion tool 330 such that thealignment key 44 is received into the alignment notch 350 formed in theinsertion tool's distal end.

The surgeon then rotates the knob 340 of the stem insertion tool 330 todrive the locking threads 346 of its locking rod 338 into the upperthreads 40 of the distal stem component 14 (see FIG. 6). As alluded toabove, the upper threads 40 are used to couple the distal stem component14 to the stem insertion tool 330 and any other loaded surgicalinstrument during implantation of the stem component.

As shown in FIG. 51, the surgeon then inserts the distal stem componentinto the intramedullary canal 22 of the patient's femur 20. The surgeonmay use a surgical mallet (not shown) to impact the superior surface 342of the knob 340 to drive the distal stem component 14 into the bonetissue within the intramedullary canal 22 of the patient's femur 20. Thesurgeon continues to drive the distal stem component 14 deeper into theintramedullary canal 22 of the patient's femur 20 until the desireddepth mark 372, 374, 376, 378 of the stem insertion tool 330 aligns withthe tip 82 of the greater trochanter 84 (see FIG. 51). During suchimplantation of the distal stem component, the “APEX” indicia located onthe stem insertion tool 330 provides a visual indicator of the locationof the apex of the bowed distal stem component 14. In such a way, thesurgeon can properly orientate bowed distal stem components 14 in theintramedullary canal 22 of the patient's femur 20.

Once the desired implant depth of the distal stem component 14 has beenachieved, the stem insertion tool 330 is removed. To do so, the surgeonrotates the knob 340 of the stem insertion tool 330 in the oppositedirection it was rotated during installation thereby rotating thelocking threads 346 formed in the distal end of the locking rod 338 in adirection which causes them to exit the upper threads 40 of the distalstem component 14. The surgeon may then remove the stem insertion tool330 from the intramedullary canal 22 of the patient's femur 20.

With the distal stem component 14 implanted, the surgeon next preparesthe patient's femur 20 to receive the proximal body component 12.Although proximal body preparation may be completed over the distalreamer 90, performing it over the implanted distal stem component 14facilitates final seating height and stem biomechanics. Thetaper-protecting sleeve 380 remains secured to the tapered post 30 ofthe distal stem component 14 during proximal body preparation.

As shown in FIG. 53, the surgeon may use the proximal reamer 390 toremove additional bone tissue to facilitate the proper seating ofproximal body component 12. To use the proximal reamer 390, the surgeonfirst couples the reamer guide shaft 250 to the implanted distal stemcomponent 14 (see FIG. 52). To do so, the surgeon aligns the reamerguide shaft's alignment flat 264 with the alignment key 44 extendingsuperiorly from the superior surface of the body 38 of the distal stemcomponent 14. In doing so, the reamer guide shaft 250 is positionedrelative to the distal stem component 14 such that the reamer guideshaft's alignment key 284 is aligned with, and received into, the keyway46 formed in the superior surface of the distal stem component 14 (seeFIG. 4) thereby inserting the distal end of the reamer guide shaft 250into the opening formed by the distal stem component's upper threads 40.As a result, the locking threads 260 of the reamer guide shaft 250 arestarted in the lower threads 42 of the distal stem component 14. Thesurgeon then locks the reamer guide shaft 250 to the distal stemcomponent 14 by inserting a manual universal hex driver 512 (see FIG.56) in the hex drive socket 258 formed in the proximal end of the reamerguide shaft's locking screw 256. The surgeon may then rotate the hexdriver to drive the reamer guide shaft's locking screw 256 therebydriving the threads 260 into the lower threads 42 of the distal stemcomponent 14. As noted above, the hex driver 512 may be embodied as atorque limiting hex driver to prevent over tightening of the lockingscrew 256.

The surgeon then selects a starting size of a proximal reamer 390. In anillustrative method, the surgeon may select a proximal reamer 390 havinga 20 mm diameter as a starting size. The male connector 420 of theselected starting proximal reamer 390 (e.g., the 20 mm proximal reamer)is then inserted into the chuck of the rotary power tool 86 or themanual handle 80. The surgeon then positions the proximal reamer 390such that the distal end 408 of its guide bore 406 is located above theproximal end of the reamer guide shaft 250. The proximal reamer 390 isthen advanced such that the reamer guide shaft 250 enters the guide bore406 of the proximal reamer 390.

Once inserted over the reamer guide shaft 250, the surgeon activates therotary power tool 86 to drive (i.e., rotate) the proximal reamer 390thereby causing the helical cutting flutes 402 of the reamer's cuttinghead 396 to abrade or otherwise cut the bone tissue of the femur 20. Theproximal reamer's depth stop 412 bottoms out on the superior surface 282of the drive socket 258 of the locking screw 256 of the reamer guideshaft 250 (see FIGS. 22 and 23) when the proximal reamer 390 is fullyseated. During such use of the proximal reamer 390, the reamer's viewingwindows 414 allow the surgeon to visualize the reamer guide shaft 250 asit is advanced along the reamer's guide bore 406. In doing so, thesurgeon can visually confirm that proper seating of the proximal reamer390 has been achieved by observing the colored mark 280 of the reamerguide shaft 250 through the viewing windows 414 formed in the proximalreamer 390. Specifically, the surgeon may visually confirm that properseating of the proximal reamer 390 has been achieved when the coloredmark 280 of the reamer guide shaft 250 (which is visible through theviewing windows 414) aligns with the colored mark 418 of the proximalreamer 390.

The surgeon then removes the proximal reamer 390 having the startingsize (e.g., 20 mm diameter) and progressively reams the patient's femur20 with increasingly larger proximal reamers 390 until desired corticalbone contact is achieved and the reamed cavity possesses the desiredfinal geometry (i.e., the shape) required to accept the proximal bodycomponent 12 selected by the surgeon.

Once the proximal reaming operation is complete, the proximal reamer 390possessing the final desired size is removed from the femur 20. Thereamer guide shaft 250 is then itself removed from the distal stemcomponent 14 by inserting a manual universal hex driver 512 (such as theone shown in FIG. 56) in the hex drive socket 258 formed in the proximalend of the reamer guide shaft's locking screw 256 and rotating thelocking screw 256 in the opposite direction it was rotated duringinstallation thereby rotating the locking threads 260 formed in thedistal end of the locking screw 256 in a direction which causes them toexit the lower threads 42 of the distal stem component 14. The reamerguide shaft 250 may then be removed from the distal stem component 14.

As shown in FIGS. 54-56, once the reamer guide shaft 250 has beenremoved from the distal stem component 14, a proximal body trialingprocedure may be performed. To do so, the surgeon first secures theproximal trial instrument 180 to the distal stem component 14 implantedin the intramedullary canal 22 of the patient's femur 20. Specifically,the surgeon selects a trial shaft 182 which corresponds to the distalstem depth that was referenced during stem insertion (i.e., based onwhich depth mark 372, 374, 376, 378 was utilized during stem insertion).To insert the trial shaft 182, the surgeon uses the trial insertion tool430. Specifically, the surgeon urges the two loops 436 of the insertiontool 430 away from one another such that the levers 432 pivot about thepin 434 and the two halves of the retention socket 442 spread slightlyaway from one another. The stem 204 of the trial shaft 182 may then beadvanced into the recess 444 of the retention socket 442. Thereafter,the surgeon squeezes or otherwise urges the two loops 436 toward oneanother thereby causing the levers 432 to pivot about the pin 434. Doingso urges the two halves of the retention socket 442 toward one anotherthereby squeezing the stem 204 of the trial shaft 182 so as to retainthe trial shaft 182 in the retention socket 442.

The distal end of the trial shaft 182 is then inserted into the superiorend of the implanted distal stem component 14. To do so, the surgeonaligns the alignment flat 210 formed on the distal end of the trialshaft 182 with the alignment key 44 extending superiorly from thesuperior surface of the body 38 of the distal stem component 14 (seeFIG. 4). In doing so, the alignment key 214 formed in the distal end ofthe trial shaft 182 is aligned with, and received into, the keyway 46formed in the superior surface of the distal stem component 14 (see FIG.4) thereby inserting the distal end of the trial shaft 182 into theopening formed by the distal stem component's upper threads 40. As aresult, the locking threads 194 of the trial shaft 182 are started inthe lower threads 42 of the distal stem component 14. The surgeon theninserts the hex driver 512 (see FIG. 56) into the hex drive head 192 ofthe trial shaft's locking screw 190. Thereafter, the surgeon rotates thehex driver 512 so as to rotate the locking threads 194 formed in thedistal end of the trial shaft's locking screw 190 thereby driving thetrial shaft's threads 194 into the lower threads 42 of the distal stemcomponent 14. Once the trial shaft 182 is secured to the distal stemcomponent 14, the trial insertion tool 430 is removed. As noted above,the hex driver 512 may be embodied as a torque limiting hex driver toprevent over tightening of the locking screw 190.

As shown in FIGS. 54 and 55, the trial neck 184 may be installed on thetrial shaft 182 prior to coupling the trial shaft 182 to the distal stemcomponent 14. If it is not installed beforehand, the trial neck 184 maybe installed on the trial shaft 182 after the shaft is coupled to thedistal stem component 14. To do so, the surgeon advances the trial neck184 such that the proximal stem 204 of the trial shaft 182 is receivedinto the bore 228 of the trial neck 184. The trial neck 184 slides downthe stem 204 of the trial shaft 182 until the inferior surface 230 ofthe trial neck's body 224 contacts the shoulder 206 formed in the body186 of the trial shaft 182 (see also FIGS. 14-17).

As shown in FIG. 57, the trial neck 184 is freely movable relative tothe trial shaft 182 at this point in the process. Upon orientating thetrial neck 184 in the proper version, it may be secured in the desiredposition by inserting a manual universal hex driver 512 (such as the oneshown in FIG. 56) in the hex drive head 242 formed in the proximal endof the trial neck's locking screw 240. The surgeon may then tighten thelocking screw 240 by rotating the hex driver. By doing so, the lockingpawl 244 of the trial neck's friction clamp 238 is urged into positionin one of the grooves of the splined surface 208 of the trial shaft 182.The locking pawl 244 contacts the sidewalls forming the groove of thesplined surface 208 thereby preventing the trial neck 184 from rotatingrelative to the trial shaft 182. As noted above, the hex driver 512 maybe embodied as a torque limiting hex driver to prevent over tighteningof the locking screw 240.

The surgeon may then install a trial femoral head (not shown) on thetrial neck 184 and perform a trial reduction to confirm appropriate leglength, offset, and component orientation. If need be after performanceof the trial reduction, the surgeon can repeat the process by looseningthe locking screw 240 of the trial neck 184, adjusting the version, andthen retightening the locking screw 240. Once a trial reduction that issatisfactory to the surgeon is complete, the proximal trial instrument180 is removed without unlocking the trial neck 184 from the trial shaft182. In other words, the orientation of the trial neck 184 relative tothe trial shaft 182 (i.e., the instrument's version) is maintainedduring removal of the proximal trial instrument 180 from the implanteddistal stem component 14. To remove the proximal trial instrument 180without disturbing the orientation of the trial neck 184 relative to thetrial shaft 182 (i.e., the instrument's version), the trial insertiontool 430 is coupled to the trial shaft 182 in the manner describedabove. The surgeon then inserts the hex driver 512 into the hex drivehead 192 of the trial shaft's locking screw 190 and rotates it in theopposite direction it was rotated during installation thereby rotatingthe locking threads 194 formed in the distal end of the trial shaft'sdrive shaft 122 in a direction which causes them to exit the lowerthreads 42 of the implanted distal stem component 14. The proximal trialinstrument 180 may then be removed from the distal stem component 14with its trial-generated version still intact.

As shown in FIGS. 58-61, the version created by the proximal trialprocedure using the proximal trial instrument 180 may be replicated tothe proximal body component 12 by use of the version-replicatinginstrument 460. Initially, the surgeon removes the taper-protectingsleeve 380 so as to expose the tapered post 30 formed in the superiorend of the distal stem component 14. The surgeon then inspects thetapered post 30 to ensure that it is dry and clear of debris. Thetapered post 30 may be washed with a pressurized saline wash andthereafter thoroughly dried if cleansing is required.

The version-replicating instrument 460 may then be coupled to theimplanted distal stem component 14. To do so, the surgeon aligns thealignment key 468 formed in the distal end of the version-replicatinginstrument 460 with the keyway 46 formed in the superior surface of thedistal stem component 14 (see FIG. 4) and inserts the distal end of theversion-replicating instrument 460 into the opening formed by the distalstem component's upper threads 40. As can be seen in FIG. 58, theproximal body component 12 may then be installed over theversion-replicating instrument 460. To do so, the surgeon advances theproximal body component 12 such that the version-replicating instrument460 is received into the tapered bore 28 of the proximal body component12. The proximal body component 12 is then slid down theversion-replicating instrument 460 such that the tapered post 30 of thedistal stem component 14 is received into its tapered bore 28.

The proximal trial instrument 180, with the trial shaft 182 and trialneck 184 still locked in the version determined during proximal trialing(see FIGS. 54-57), is then coupled to the proximal end of theversion-replicating instrument 460. Specifically, as shown in FIGS. 60and 61, the distal end 212 of the trial shaft 182 of the proximal trialinstrument 180 (see FIGS. 14-16) is inserted into the blind hole 470formed in the proximal end of the version-replicating instrument 460. Indoing so, the alignment key 214 formed on the trial shaft 182 of theproximal trial instrument 180 is received into the alignment slot 474formed in the version-replicating instrument's shaft 462.

The proximal body component 12 may then be rotated to match the versionof the proximal trial instrument 180. Namely, the surgeon can view downthe longitudinal axis of the version-replicating instrument 460 androtate the proximal body component 12 so that its neck 16 is alignedwith the elongated neck 226 of the trial neck 184. Thus, the proximalbody component 12 is placed in the same version that was obtained duringproximal trialing (see FIGS. 54-57). Once the version of the proximaltrial instrument 180 has been replicated in the position of the proximalbody component 12, the proximal trial instrument 180 is then lifted offof the proximal end of the version-replicating instrument 460.

As shown in FIGS. 62 and 63, once the proximal trial instrument 180 hasbeen removed, a taper tamp 540 may be slipped over theversion-replicating instrument 460. As can be seen in FIG. 62, the tapertamp 540 has an elongated blind bore 542 formed therein. The bore 542 issized such that the distal edge 544 of the taper tamp 540 contacts theshoulder 52 of the proximal body component 12 during use of the tamp 540without disturbing the version-replicating instrument 460. In otherwords, once slipped over the version-replicating instrument 460, thesurgeon may lightly tap the taper tamp 540 with a surgical mallet toinitially engage the taper lock connection between the distal stemcomponent 14 and the proximal body component 12 without theversion-replicating instrument 460 bottoming out in the bore 542. Asdescribed above, each of the colored depth marks 482, 484, 486, 488 onthe version-replicating instrument 460 corresponds to the location ofthe shoulder 52 of the proximal body component 12 once its implanted. Assuch, the colored depth marks 482, 484, 486, 488 may be used as a depthmark to ensure the tapered post 30 of the distal stem component 14 andthe tapered bore 28 of the proximal body component 12 are notsignificantly dislocated prior to removal of the version-replicatinginstrument 460. The taper tamp 540 and version-replicating instrument460 are then removed. The surgeon then uses a taper assembly tool, suchas the taper assembly tool described in U.S. patent application Ser. No.12/815,915 (filed Jun. 15, 2010), to fully engage the taper lockconnection between the distal stem component 14 and the proximal bodycomponent 12.

The surgeon then obtains an appropriately sized locking bolt 504. Thelocking bolt 504 is shown in more detail in FIGS. 67-70. As can be seen,the locking bolt 504 has a shank 524 extending away from its head 502.The shank 524 has a number of external threads 526 formed therein. Thelocking bolt's threads 526 are smaller than the upper threads 40 of thedistal stem component 14 such that they pass therethrough without threadengagement during installation of the locking bolt 504. Instead, thelocking bolt's threads 526 are sized for thread engagement with thelower threads 42 of the distal stem component 14. As such, in theillustrative embodiment described herein, the locking bolt's threads 526are embodied as M6 threads. Moreover, like the lower threads 42 of thedistal stem component 14, the locking bolt's threads 526 are embodied asmodified threads designed to relieve stress risers. In particular, ascan be seen best in FIGS. 68-69, the locking bolt's threads 526 areembodied as modified MJ6×1.0 ground threads.

A stepped washer 528 is installed on the locking bolt 504. The steppedwasher 528 functions as a biasing member to resist loosening of thelocking bolt 504 once it is installed. As can be seen in FIGS. 67-70,the flange of the bolt head 502 functions as a compressor to the steppedwasher 528. A clip 530 maintains the stepped washer 528 on the shank 524of the locking bolt 504 prior to installation.

Both the locking bolt 504 and the stepped washer 528 may be constructedfrom a medical-grade metal such as stainless steel, cobalt chrome, ortitanium, although other metals or alloys may be used. The clip 530 maybe constructed from a rigid polymer such as polyetheretherketone (PEEK).

Returning back to FIG. 64, once the surgeon has obtained anappropriately sized locking bolt 504, the locking bolt 504 is theninstalled to act as a secondary lock between the proximal body component12 to the distal stem component 14. To do so, the surgeon inserts thelocking bolt 504 through the countersunk cavity 32 of the proximal bodycomponent 12 (see FIG. 64). Thereafter, the surgeon uses finger pressureto turn the locking bolt 504 thereby causing initial thread engagementbetween the threads 526 of the locking bolt 504 and the lower threads 42of the distal stem component 14. The surgeon then applies apredetermined torque to the locking bolt 504. To do so, the surgeon usesthe stem stabilizer 490 in conjunction with a torque wrench such as theT-handle torque wrench 520 shown in FIGS. 65 and 66. As shown in FIG.65, the surgeon first couples the drive socket 522 of the torque wrench52 to the square-type drive head 496 formed in the proximal end of thestem stabilizer's drive rod 514. Once coupled in such a manner, rotationof the torque wrench 520 causes rotation of the stem stabilizer's driverod 514 and hence the drive socket 498 formed in its distal end.

The stem stabilizer 490, with the torque wrench 520 secured thereto, isthen assembled on the implanted femoral prosthesis 10. In particular,the surgeon advances the stem stabilizer 490 into contact with thefemoral prosthesis 10 such that the head 502 of the locking bolt 504 isreceived into the drive socket 498 of the stem stabilizer's drive rod514 and the elongated neck 16 of the proximal body component 12 iscaptured between the tines 510 of the stem stabilizer's fork 508 (seeFIG. 66).

Once the stem stabilizer 490 is secured to the implanted femoralprosthesis 10 in such a manner, the surgeon tightens the locking bolt504. Specifically, the surgeon turns the T-handle torque wrench 520until it clicks. Such an audible click indicates that the appropriatetorque has been applied to the locking bolt 504 thereby providingconfirmation to the surgeon that the locking bolt 504 has been fullyseated. The stem stabilizer 490, with the torque wrench 520 securedthereto, is then removed from the implanted femoral prosthesis 10.

If for some reason the surgeon needs to disengage the taper lockconnection between the distal stem component 14 and the proximal bodycomponent 12, the surgeon may then use a taper disassembly tool, such asthe taper disassembly tool described in U.S. patent application Ser. No.12/873,612 (filed Sep. 1, 2010). Prior to using such a disassembly tool,the surgeon first removes the locking bolt 504.

Referring now to FIGS. 71-73, there is shown another embodiment of atrial insertion tool 630 that may be secured to the proximal trialinstrument 180 to facilitate its attachment to the distal reamer 90 orthe distal stem component 14 implanted in the intramedullary canal 22 ofthe patient's femur 20. The trial insertion tool 630 includes a body 632having an elongated bore 634 extending therethrough. A sleeve 636 ispositioned around the insertion tool's body 632. The sleeve 636 isimmovably coupled to the outer surface of the insertion tool's body 632,such as by, for example, overmolding. The sleeve 636 functions as a gripfor allowing the surgeon to hold the trail insertion tool 630 duringassembly of the proximal trial instrument 180 to the distal reamer 90 orthe distal stem component 14.

A drive rod 638 is captured in the bore 634. A knob 640 is secured tothe proximal end of the drive rod 638. Rotation of the knob 640 causesrotation of the drive rod 638. The drive rod 638 includes a hex drivetip 652 located at its distal end (see FIGS. 72 and 73). When the hexdrive tip 652 is positioned in the hex drive head 192 of the proximaltrial shaft 182 and rotated, the locking threads 194 formed in thedistal end of the trial shaft's drive shaft 122 are likewise rotated. Asdescribed above, such rotation of the trial shaft's drive shaft 122drives the trial shaft's threads 194 into the lower threads 42 of thedistal stem component 14 or the threads 112 of the distal reamer 90.

The distal end of the body 632 of the trial insertion tool 630 has aretention socket 642 formed therein. The retention socket 642 is sizedand shaped to receive the stem 204 formed in the proximal end 202 of thetrial shaft 182. In particular, as shown in the cross sectional view ofFIG. 73, the retention socket 642 has a round recess 644 formed therein.The inner diameter of the recess 644 is sized to closely mimic the outerdiameter of the stem 204 of the trial shaft 182 so as to receive ittherein. As can also be seen in the cross sectional view of FIG. 73, theretention socket 642 has an alignment pin 646 extending therethrough.The alignment pin 646 is arranged substantially perpendicular to thelongitudinal axis of the trial insertion tool 630. The alignment pin 646essentially “flattens” one side of the round recess 644. The alignmentpin 646 aligns the trial shaft 182 of the proximal trial instrument 180in a desired orientation relative to the trial insertion tool 630.

As can be seen in the cross section of FIG. 72, a retainer ring 648 ispositioned in the sidewall 650 that defines the recess 644 of the trialinsertion tool's retention socket 642. The retainer ring 648 snapsaround a groove on the outer surface the stem 204 of the trial shaft 182to retain the trial shaft 182 of the proximal trial instrument 180 inthe retention socket 642.

The metallic components of the trial insertion tool 630 (e.g., theinsertion tool's body 632, drive rod 638, et cetera) may be constructedfrom a medical-grade metal such as stainless steel, cobalt chrome, ortitanium, although other metals or alloys may be used. Moreover, in someembodiments, rigid polymers such as polyetheretherketone (PEEK) may alsobe used. The sleeve 636 may be constructed from a polymer such as delrinor silicone.

While the disclosure has been illustrated and described in detail in thedrawings and foregoing description, such an illustration and descriptionis to be considered as exemplary and not restrictive in character, itbeing understood that only illustrative embodiments have been shown anddescribed and that all changes and modifications that come within thespirit of the disclosure are desired to be protected.

There are a plurality of advantages of the present disclosure arisingfrom the various features of the apparatus, system, and method describedherein. It will be noted that alternative embodiments of the apparatus,system, and method of the present disclosure may not include all of thefeatures described yet still benefit from at least some of theadvantages of such features. Those of ordinary skill in the art mayreadily devise their own implementations of the apparatus, system, andmethod that incorporate one or more of the features of the presentinvention and fall within the spirit and scope of the presentdisclosure.

1. A method of performing a surgical procedure to implant an orthopaedichip prosthesis, comprising: implanting a distal stem component into anintramedullary canal of a patient's femur, installing a trial shaft tothe proximal end of the distal stem component positioned in theintramedullary canal of a patient's femur, installing a discrete trialneck on the trial shaft, and rotating the trial neck relative to thetrial shaft so as to position the trial neck in a number of differentversions.
 2. The method of claim 1, wherein: the trial shaft comprises arotatable locking screw having a number of threads formed in a distalend thereof, and installing the trial shaft to the proximal end of thedistal stem component comprises threading the threads of the lockingscrew into a threaded bore of the distal stem component.
 3. The methodof claim 1, wherein the trial neck is installed on the trial shaft priorto installation of the trial shaft to the implanted distal stemcomponent.
 4. The method of claim 1, wherein the trial neck is installedon the trial shaft after the trial shaft is installed to the implanteddistal stem component.
 5. The method of claim 1, further comprisinglocking the trial neck relative to the trial shaft so as to maintain thetrial neck in a selected version of the number of different versions. 6.The method of claim 5, further comprising uninstalling the trial shaftfrom the proximal end of the distal stem component positioned in theintramedullary canal of the patient's femur with the trial neck lockedrelative to the trial shaft in the selected version.
 7. The method ofclaim 6, further comprising: installing a version-replicating instrumentto the proximal end of the distal stem component, and installing thetrial shaft, with the trial neck locked relative to the trial shaft inthe selected version, on the version-replicating instrument.
 8. Themethod of claim 7, further comprising: installing a proximal bodycomponent on the version-replicating instrument, and rotating theproximal body component so that the version of the proximal bodycomponent matches the selected version of the trial neck relative to thetrial shaft.
 9. The method of claim 8, wherein the proximal bodycomponent is installed on the version-replicating instrument prior toinstallation of the trial shaft on the version-replicating instrument.10. A method of performing a surgical procedure to implant anorthopaedic hip prosthesis, comprising: implanting a distal stemcomponent into an intramedullary canal of a patient's femur, installinga trial shaft to the proximal end of the implanted distal stemcomponent, installing a discrete trial neck on the trial shaft androtating the trial neck relative to the trial shaft so as to positionthe trial neck in a selected version, and locking the trial neckrelative to the trial shaft in the selected version.
 11. The method ofclaim 10, wherein: the trial shaft comprises a rotatable locking screwhaving a number of threads formed in a distal end thereof, andinstalling the trial shaft to the implanted distal stem componentcomprises threading the threads of the locking screw into a threadedbore of the distal stem component.
 12. The method of claim 10, whereinthe trial neck is installed on the trial shaft prior to installation ofthe trial shaft to the implanted distal stem component.
 13. The methodof claim 10, wherein the trial neck is installed on the trial shaftafter the trial shaft is installed to the implanted distal stemcomponent.
 14. The method of claim 10, further comprising uninstallingthe trial shaft from the implanted distal stem component with the trialneck locked relative to the trial shaft in the selected version.
 15. Themethod of claim 14, further comprising: installing a version-replicatinginstrument to the proximal end of the implanted distal stem component,and installing the trial shaft, with the trial neck locked relative tothe trial shaft in the selected version, on the version-replicatinginstrument.
 16. The method of claim 15, further comprising: installing aproximal body component on the version-replicating instrument, androtating the proximal body component so that the version of the proximalbody component matches the selected version of the trial neck relativeto the trial shaft.
 17. The method of claim 16, wherein the proximalbody component is installed on the version-replicating instrument priorto installation of the trial shaft on the version-replicatinginstrument.